Oligo- and polyfurans, preparation and uses thereof

ABSTRACT

This invention is directed to oligofurans, process of preparation and uses thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of PCT InternationalApplication No. PCT/IL2010/000700, International Filing Date Aug. 26,2010, claiming priority of U.S. Patent Application 61/237,330, filedAug. 27, 2009, which are incorporated in their entirety herein byreference.

FIELD OF THE INVENTION

This invention is directed to oligofurans, process of preparation anduses thereof.

BACKGROUND OF THE INVENTION

Organic molecules with long π-conjugation have received much attentionas advanced materials and as the building blocks of nano-scale devicesfor use in solar cells, organic light emitting diodes (OLEDs), organicfield effect transistors (OFETs), organic light emitting transistors(OLETs), batteries, electro-luminescent material and sensors. Stability,good solid state packing, processability, rigidity/planarity, highfluorescence, and a HOMO-LUMO gap in the semiconductor region (whichalso leads to absorption/emission in the visible range) are among themain requirements for useful advanced organic electronic materials to beapplied as functional materials in organic electronic nano-technologies.Those materials are also used for various industrial applications suchas antistatic coatings, dyes or pigments.

The conjugated chains and the electrical and optical properties of thesepolymers are influenced by the electronegativity of the heteroatom.

The synthesis of polyfuran by electrochemical means requires highvoltage for the electropolymerization (1.8-2.5V) which results inirreversible oxidation of the polymer. Electropolymerization process,using terfuran provides milder polymerization due to its lower oxidationpotential compared to furan.

Chemical polymerization of furan using a number of oxidizing agentsusing oxygen and a Ni catalyst, ferric chloride, and potassiumferricyanide resulted in only -polymers of poor quality resulting in lowconjugation length. Another oxidizing agent which was used is pyridiniumchlorochromate (PCC) resulting also in poor quality polymers.

Accordingly, it is an object of the present application to provide highquality and stable oligofurans and polyfurans.

SUMMARY OF THE INVENTION

In one embodiment, this invention provides an oligofuran represented bythe structure of formula IV:

wherein

-   R₁, R₂, R₃ and R₄ are independently hydrogen, C₁-C₁₈ alkyl, C₁-C₁₈    alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-heterocycloalkyl, (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈    alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈    alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl),    NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈ alkyl)][C(O)(C₁-C₁₈ alkyl)],    halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl),    phenyl, aryl, cycloalkyl or heteroaryl; wherein said alkyl, aryl,    cycloalkyl and heteroaryl groups are optionally substituted with 1-3    groups comprising halide, [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl),    NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂ combine to form a 4-8 membered ring comprising 0-3 double    bonds and 0-3 heteroatoms selected from O, N, Se or S wherein said    4-8 membered ring is optionally substituted with 1-3 groups    comprising C₁-C₁₈-alkyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆    alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or    N[(C₁-C₆alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl    and heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)];-   m is an integer between 1-50; and-   n is an integer between 1-50; wherein if R₁ and R₂ are hydrogens    then [n+2m] is not 3 or 4.

In one embodiment, this invention provides a process for the preparationof oligofuran of formula III(n+2m) comprising reacting a compoundrepresented by the structure of formula I:

with 2-(tributyltin)-oligofuran of formula II:

to yield oligofuran of formula III(n+2m):

wherein X is Br or I;n is an integer between 1-20; andm is an integer between 1-20.

In one embodiment, this invention provides an oligofuran of formulaIII(n+2m) prepared by the process described herein above.

In one embodiment, this invention provides an oligofuran represented bythe structure of formula XIII:

wherein

-   R₁, R₁′, R₁″, R₂, R₂′, R₂″, R₃ and R₄ are independently hydrogen,    C₁-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆    alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl, (C₀-C₁₈    alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂,    halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl),    NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈    alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈    alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or    heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl    groups are optionally substituted with 1-3 groups comprising halide,    [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl),    O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆alkyl)    or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂; R₁′ and R₂′; R₁″ and R₂″ combine to form a 4-8 membered    ring comprising 0-3 double bonds and 0-3 heteroatoms selected from    O, N, Se or S wherein said 4-8 membered ring is optionally    substituted with 1-3 groups comprising C₁-C₁₈-alkyl, (C₀-C₆    alkyl)-cycloalkyl, (C₀-C₆ alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or    N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl    and heteroaryl groups of said (C₀-C₆alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)];-   m is an integer between 1-50;-   m′ is an integer between 0-50 and-   n is an integer between 1-50;    wherein if R₁, R₁′, R₁″ and R₂, R₂′, R₂″ are hydrogens then [n+m+m′]    is not 3 or 4.

In one embodiment, the oligofurans of this invention are fluorescent.

In one embodiment, this invention provides a fluorescent markercomprising the oligofurans of this invention. In one embodiment, thisinvention provides a field effect transistor device comprising theoligofurans of this invention. In one embodiment, this inventionprovides a light emitting transistor device comprising the oligofuransof this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 depicts a synthetic scheme for the preparation of oligofurans ofthis invention.

FIG. 2 depicts (a) Cyclic Voltammetry (CV) of oligofurans 5F-8F inpropylene carbonate (PC) and 0.1M tetra-n-butylammoniumtetrafluoroborate (TBABF₄), scan rate: 50 mV/sec; (b) Repetitive CVscans of 6F in 1,2-dichloroethane with 0.1M TBABF, scan rate 100 mV/s,Fc/Fc⁺=0.34 V vs. SCE under these conditions. (c) Multi-sweepelectropolymerization of 6F on a Pt electrode in 1,2-dichloroethane,scan rate, 50 mV s⁻¹, 0.1 M TBABF₄, reference electrode Ag/AgCl,Fc/Fc⁺=0.34 V vs. SCE under these conditions

FIG. 3 depicts Thermogravimetric Analysis (TGA) of oligofurans (a) 5F-8Fand (b) 9F under N₂, rate: 5° C./min.

FIG. 4 depicts Differential Scanning calorimetry (DSC) of oligofurans5F-8F under N₂, rate: 10° C./min.

FIG. 5 Crystal packing of α-terfuran (3F). Hydrogen atoms are emittedfor clarity.

FIG. 6 Crystal packing of α-tetrafuran (4F). Hydrogen atoms are emittedfor clarity.

FIG. 7 Crystal packing of α-sexifuran (6F)

FIG. 8 UV/VIS and fluorescent spectra of oligofurans 5F-9F (i.e 5Frefers to α-pentafuran; 6F to α-sexifuran; 7F to α-hepafuran; 8F toα-octafuran and 9F to α-nonafuran. (A) absorbance in dioxane; (B)fluorescence of 5F-9F in dioxane (C) fluorescence spectra of 6F in thesolid state (powder) and in solution (dioxane).

FIG. 9. depicts a synthetic scheme of oligofuran IV-B (DH-6F,dihexyl-6F).

FIG. 10 depicts DSC Differential scanning calorimetry (DSC) ofoligofurans 6F and DH-6F under N₂, rate: 5° C./min.

FIG. 11 depicts thermogravimetric analysis (TGA) of oligofurans 6F, 8Fand DH-6F under N₂, Rate: 5° C./min.

FIG. 12 depicts fluorescence spectra of 6F, DM-6F (dimethyl-sexifuran)and DH-6F (dihexyl-sexifuran).

FIG. 13 depicts AFM images and cross section diagrams of (a) DH-6F afterdeposition times of 20 sec (sub ML regime), (b) DH-6F after 120 sec.deposition (3 layers thickness), (c) 8F after deposition times of 20 secand (d) 60 sec, (e) 6F after deposition time of 20 and (f) 60 sec, onSi/SiO₂.

FIG. 14 depicts XRD patterns for vacuum deposited films of (a) DH-6F (b)6F and (c) 8F.

FIG. 15 depicts Differential Pulse Voltammogram (DPV) of oligofurans.Conditions: scan rate, 20 mV s⁻¹, 0.1M TBABF₄ in PC reference electrodeAg/AgCl, Fc/Fc⁺=0.34 V vs. SCE under these conditions.

FIG. 16 depicts calculated (B3LYP/6-31G(d)) relative energy vs. twistangle required for spiral twisting of 6F and 6T.

FIG. 17 depicts synthetic route to DPFB-6F and DPFB-2F oligofurans.

FIG. 18 depicts absorption and fluorescence spectra of DPFB-6F indioxane.

FIG. 19 depicts a synthetic route to long β-alkyl-oligofurans.

FIG. 20 depicts a synthetic route to long β-allyl-oligofurans.

FIG. 21 depicts spectroelectrochemistry of 3″-octyl-5F as a function ofapplied potential in acetonitrile (electrolyte: TBA-CF₃SO₃ 0.1M, workingelectrode: ITO on glass, counter electrode: Pt disk, reference electrodeAg/AgCl).

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

In one embodiment, this invention is directed to the synthesis andcharacterization of a series of stable α-oligofurans, which are highlyfluorescent (compared to oligothiophenes and alternating furan-thiopheneoligomers), electron rich, and exhibit tighter herringbone solid statepacking, greater rigidity, and greater solubility than oligothiophenes.

In one embodiment, this invention provides an oligofuran represented bythe structure of formula III:

wherein m is an integer between 1-20; andn is an integer between 1-20, wherein [n+2m] is not 3, or 4.

In another embodiment, [n+2m] of the oligomer of formula III is 5. Inanother embodiment, [n+2m] of the oligomer of formula III is 6. Inanother embodiment, [n+2m] of the oligomer of formula III is 7. Inanother embodiment, [n+2m] of the oligomer of formula III is 8. Inanother embodiment, [n+2m] of the oligomer of formula III is 9. Inanother embodiment, [n+2m] of the oligomer of formula III is 10. Inanother embodiment, [n+2m] of the oligomer of formula III is between5-10. In another embodiment, [n+2m] of the oligomer of formula III isbetween 5-15. In another embodiment, [n+2m] of the oligomer of formulaIII is between 5-20. In another embodiment, [n+2m] of the oligomer offormula III is between 5-30. In another embodiment, [n+2m] of theoligomer of formula III is between 11-15. In another embodiment, [n+2m]of the oligomer of formula III is between 15-20. In another embodiment,[n+2m] of the oligomer of formula III is between 20-25. In anotherembodiment, [n+2m] of the oligomer of formula III is between 25-30. Inanother embodiment, [n+2m] of the oligomer of formula III is between30-35. In another embodiment, [n+2m] of the oligomer of formula III isbetween 35-40. In another embodiment, [n+2m] of the oligomer of formulaIII is between 40-45. In another embodiment, [n+2m] of the oligomer offormula III is between 45-50. In another embodiment, [n+2m] of theoligomer of formula III is between 50-55. In another embodiment, [n+2m]of the oligomer of formula III is between 55-60. In another embodiment,[n+2m] of the oligomer of formula III is between 30-60.

In another embodiment, [n] of the oligomer of formula III is 1. Inanother embodiment, [n] of the oligomer of formula III is 2. In anotherembodiment, [n] of the oligomer of formula III is 3. In anotherembodiment, [n] of the oligomer of formula III is 4. In anotherembodiment, [n] of the oligomer of formula III is an integer between3-5. In another embodiment, [n] of the oligomer of formula III is aninteger between 3-8. In another embodiment, [n] of the oligomer offormula III is an integer between 5-10. In another embodiment, [n] ofthe oligomer of formula III is an integer between 10-20. In anotherembodiment, [n] of the oligomer of formula III is an integer between15-20.

In another embodiment, [m] of the oligomer of formula III is 1. Inanother embodiment, [m] of the oligomer of formula III is 2. In anotherembodiment, [m] of the oligomer of formula III is 3. In anotherembodiment, [m] of the oligomer of formula III is 4. In anotherembodiment, [m] of the oligomer of formula III is an integer between3-5. In another embodiment, [m] of the oligomer of formula III is aninteger between 3-8. In another embodiment, [m] of the oligomer offormula III is an integer between 5-10. In another embodiment, [m] ofthe oligomer of formula III is an integer between 10-20. In anotherembodiment, [m] of the oligomer of formula III is an integer between15-20.

In another embodiment, [m] of the oligomer of formula III is 2 and [n]is 1. In another embodiment, [m] of the oligomer of formula III is and[n] is 2. In another embodiment, [m] of the oligomer of formula III is 2and [n] is 3. In another embodiment, [m] of the oligomer of formula IIIis 3 and [n] is 2. In another embodiment, [m] of the oligomer of formulaIII is 3 and [n] is 3.

In one embodiment, this invention provides an oligofuran represented bythe structure of formula IV:

wherein

-   R₁, R₂, R₃ and R₄ are independently hydrogen, C₁-C₁₈ alkyl, C₁-C₁₈    alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-heterocycloalkyl, (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈    alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈    alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl),    NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈ alkyl)][C(O)(C₁-C₁₈ alkyl)],    halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl),    phenyl, aryl, cycloalkyl or heteroaryl; wherein said alkyl, aryl,    cycloalkyl and heteroaryl groups are optionally substituted with 1-3    groups comprising halide, [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl),    NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂ combine to form a 4-8 membered ring comprising 0-3 double    bonds and 0-3 heteroatoms selected from O, N, Se or S wherein said    4-8 membered ring is optionally substituted with 1-3 groups    comprising C₁-C₁₈-alkyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆    alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl and    heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)];-   m is an integer between 1-50; and-   n is an integer between 1-50;    wherein if R₁ and R₂ are hydrogens then [n+2m] is not 3 or 4.

In one embodiment, R₁ and R₂ of the oligomer of formula IV are the same.In another embodiment R₁ and R₂ of the oligomer of formula IV aredifferent. In another embodiment R₁ of formula IV is hydrogen. Inanother embodiment R₂ of formula IV is hydrogen. In another embodimentR₁ and R₂ of formula IV are hydrogens. In another embodiment R₁ and R₂are not hydrogens. In another embodiment R₁ of formula IV is an alkyl.In another embodiment R₂ of formula IV is an alkyl. In anotherembodiment R₁ and R₂ are an alkyl. In another embodiment R₁ and R₂ offormula IV are independently hydroxyalkyl. In another embodiment R₁ andR₂ of formula IV are independently halo-alkyl. In another embodiment R₁and R₂ of formula IV are independently alkyl-aryl. In another embodimentR₁ and R₂ of formula N are independently alkyl-aryl, wherein the aryl issubstituted by an halogen. In another embodiment R₁ and R₂ of formula IVare independently alkyl-aryl, wherein the aryl is substituted by between1-5 fluoro groups. In another embodiment R₁ and R₂ of formula IV areindependently cycloalkyl, hetrocycloalkyl, aryl, or heteroaryl;

In one embodiment, R₁ and R₂ form together a 6 membered cycloalkyl ring.In one embodiment, R₁ and R₂ form together a 6 membered heterocyclicring. In one embodiment, R₁ and R₂ form together a 6 membered aryl ring.In one embodiment, R₁ and R₂ form together a 6 membered heteroaryl ring.In one embodiment, R₁ and R₂ form together a 5 membered cycloalkyl ring.In one embodiment, R₁ and R₂ form together a 5 membered heterocyclicring. In one embodiment, R₁ and R₂ form together a 5 membered aryl ring.In one embodiment, R₁ and R₂ form together a 5 membered heteroaryl ring.

In one embodiment, R₃ and R₄ of the oligomer of formula IV are the same.In another embodiment R₃ and R₄ of the oligomer of formula IV aredifferent. In another embodiment R₃ of formula IV is hydrogen. Inanother embodiment R₄ of formula IV is hydrogen. In another embodimentR₃ and R₄ of formula IV are hydrogens. In another embodiment R₃ and R₄are not hydrogens. In another embodiment R₃ of formula IV is an alkyl.In another embodiment R₄ of formula IV is an alkyl. In anotherembodiment R₃ and R₄ are an alkyl. In another embodiment R₃ and R₄ arehexyl. In another embodiment R₃ and R₄ are methyl. In another embodimentR₃ and R₄ are ethyl-hexyl. In another embodiment R₃ and R₄ are O-alkyl.In another embodiment R₃ and R₄ are methoxy group. In another embodimentR₃ and R₃ are alkyl-phenyl. In another embodiment R₃ and R₄ arealkyl-pentafluorophenyl. In another embodiment R₃ and R₄ arealkyl-fluorophenyl. In another embodiment R₃ and R₄ of formula IV areindependently hydroxyalkyl. In another embodiment R₃ and R₄ of formulaIV are independently halo-alkyl. In another embodiment R₃ and R₄ offormula IV are independently alkyl-aryl. In another embodiment R₃ and R₄of formula IV are independently cycloalkyl, hetrocycloalkyl, aryl, orheteroaryl.

In another embodiment, [n+2m] of the oligomer of formula IV is 5. Inanother embodiment, [n+2m] of the oligomer of formula IV is 6. Inanother embodiment, [n+2m] of the oligomer of formula IV is 7. Inanother embodiment, [n+2m] of the oligomer of formula IV is 8. Inanother embodiment, [n+2m] of the oligomer of formula IV is 9. Inanother embodiment, [n+2m] of the oligomer of formula IV is 10. Inanother embodiment, [n+2m] of the oligomer of formula III is between5-10. In another embodiment, [n+2m] of the oligomer of formula III isbetween 5-15. In another embodiment, [n+2m] of the oligomer of formulaIII is between 5-20. In another embodiment, [n+2m] of the oligomer offormula III is between 5-30. In another embodiment, [n+2m] of theoligomer of formula IV is between 11-15. In another embodiment, [n+2m]of the oligomer of formula IV is between 15-20. In another embodiment,[n+2m] of the oligomer of formula IV is between 20-25. In anotherembodiment, [n+2m] of the oligomer of formula IV is between 25-40. Inanother embodiment, [n+2m] of the oligomer of formula IV is between40-60. In another embodiment, [n+2m] of the oligomer of formula IV isbetween 60-80. In another embodiment, [n+2m] of the oligomer of formulaIV is between 80-100. In another embodiment, [n+2m] of the oligomer offormula IV is between 100-120. In another embodiment, [n+2m] of theoligomer of formula IV is between 120-130. In another embodiment, [n+2m]of the oligomer of formula IV is between 130-140. In another embodiment,[n+2m] of the oligomer of formula IV is between 140-150.

In another embodiment, [n] of the oligomer of formula IV is 1. Inanother embodiment, [n] of the oligomer of formula IV is 2. In anotherembodiment, [n] of the oligomer of formula IV is 3. In anotherembodiment, [n] of the oligomer of formula IV is 4. In anotherembodiment, [n] of the oligomer of formula IV is an integer between 3-5.In another embodiment, [n] of the oligomer of formula IV is an integerbetween 3-8. In another embodiment, [n] of the oligomer of formula IV isan integer between 5-10. In another embodiment, [n] of the oligomer offormula IV is an integer between 10-20. In another embodiment, [n] ofthe oligomer of formula IV is an integer between 15-20. In anotherembodiment, [n] of the oligomer of formula IV is an integer between20-25. In another embodiment, [n] of the oligomer of formula IV is aninteger between 25-30. In another embodiment, [n] of the oligomer offormula IV is an integer between 30-35. In another embodiment, [n] ofthe oligomer of formula IV is an integer between 35-50. In anotherembodiment, [n] of the oligomer of formula IV is an integer between25-50.

In another embodiment, [m] of the oligomer of formula IV is 1. Inanother embodiment, [m] of the oligomer of formula IV is 2. In anotherembodiment, [m] of the oligomer of formula IV is 3. In anotherembodiment, [m] of the oligomer of formula IV is 4. In anotherembodiment, [m] of the oligomer of formula IV is an integer between 3-5.In another embodiment, [m] of the oligomer of formula IV is an integerbetween 3-8. In another embodiment, [m] of the oligomer of formula IV isan integer between 5-10. In another embodiment, [m] of the oligomer offormula IV is an integer between 10-20. In another embodiment, [m] ofthe oligomer of formula IV is an integer between 15-20. In anotherembodiment, [m] of the oligomer of formula IV is an integer between20-25. In another embodiment, [m] of the oligomer of formula IV is aninteger between 25-30. In another embodiment, [m] of the oligomer offormula IV is an integer between 30-35. In another embodiment, [m] ofthe oligomer of formula IV is an integer between 35-50. In anotherembodiment, [m] of the oligomer of formula IV is an integer between25-50.

In another embodiment, [m] of the oligomer of formula IV is 2 and [n]is 1. In another embodiment, [m] of the oligomer of formula IV is and[n] is 2. In another embodiment, [m] of the oligomer of formula IV is 2and [n] is 3. In another embodiment, [m] of the oligomer of formula IVis 3 and [n] is 2. In another embodiment, [m] of the oligomer of formulaIV is 3 and [n] is 3.

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of 5F:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of 6F:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of 7F:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of 8F:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of 9F:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of formula IV-A:

-   wherein [n+2m] are as described for formula IV and R₃ and R₄ are    independently an alkyl chain between 2-18 carbons. In another    embodiment, R₃ and R₄ are independently an alkyl chain between 2 to    12 carbons. In another embodiment, R₃ and R₄ are independently an    alkyl chain between 2 to 10 carbons. In another embodiment, R₃ and    R₄ are independently an alkyl chain between 2 to 8 carbons. In    another embodiment, R₃ and R₄ are independently an alkyl chain    between 3 to 8 carbons. In another embodiment, R₃ and R₄ are    independently an alkyl chain having 6 carbons. In another    embodiment, R₃ and R₄ are independently a substituted or    unsubstituted phenyl ring. In another embodiment, R₃ and R₄ are    independently a phenyl ring substituted by a halogen. In another    embodiment, R₃ and R₄ are independently a phenyl ring substituted by    between 1-5 fluorine (F) groups. In another embodiment, R₃ and R₄    are independently a phenyl ring substituted by penta-fluorine. In    another embodiment, R₃ and R₄ are independently aryl, cycloalkyl and    heteroaryl groups.

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of formula DH-6F wherein the oligofuranpossess dihexyl chains and sexifuran groups:

In one embodiment, this invention is directed to an oligofuranrepresented by the structure of formula DPFB-6F:

In one embodiment, this invention provides a process for the preparationoligofurans and polyfurans.

In one embodiment, this invention provides a process for the preparationof oligofuran of formula III(n+2m) comprising reacting a compoundrepresented by the structure of formula I:

with 2-(tributyltin)-oligofuran of formula II:

to yield oligofuran of formula III(n+2m):

wherein X is Br or I;n is an integer between 1-20; andm is an integer between 1-20.

In one embodiment, this invention provides a process for the preparationof oligofuran of formula IV(n+2m) comprising reacting a compoundrepresented by the structure of formula V(n):

with 2-(tributyltin)-oligofuran of formula VI(m):

to yield oligofuran of formula IV(n+2m):

wherein

-   R₁, R₂, R₃ and R₄ are independently hydrogen, C₁-C₁₈ alkyl, C₁-C₁₈    alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-heterocycloalkyl, (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈    alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈    alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl),    NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈ alkyl)][C(O)(C₁-C₁₈ alkyl)],    halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl),    phenyl, aryl, cycloalkyl or heteroaryl; wherein said alkyl, aryl,    cycloalkyl and heteroaryl groups are optionally substituted with 1-3    groups comprising halide, [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl),    NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂ combine to form a 4-8 membered ring comprising 0-3 double    bonds and 0-3 heteroatoms selected from O, N, Se or S wherein said    4-8 membered ring is optionally substituted with 1-3 groups    comprising C₁-C₁₈-alkyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆    alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl and    heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)]; and-   X is Br or I.

In one embodiment, this invention provides a process for the preparationof oligofuran of formula III(m+2n) comprising reacting a compoundrepresented by the structure of formula VII:

with 2,5-(tributyltin)-oligofuran of formula VIII:

to yield oligofuran of formula III:

wherein X is Br or I;n is an integer between 1-20; andm is an integer between 1-20, wherein m+2n is not 3 or 4.

In one embodiment, this invention provides a process for the preparationof oligofuran of formula IV(m+2n) comprising reacting a compoundrepresented by the structure of formula IX:

with 2,5-(tributyltin)-oligofuran of formula X:

to yield oligofuran of formula IV(m+2n):

wherein

-   R₁, R₂, R₃ and R₄ are independently hydrogen, C₁-C₁₈ alkyl, C₁-C₁₈    alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-heterocycloalkyl, (C₀-C₁₈ (C₀-C₁₈ alkyl)-heteroaryl, CN,    CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₁-C₁₈    alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₆ alkyl) or    N[(C₁-C₆ alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl),    hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl,    cycloalkyl or heteroaryl; wherein said alkyl, aryl, cycloalkyl and    heteroaryl groups are optionally substituted with 1-3 groups    comprising halide, [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆    alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl),    NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂ combine to form a 4-8 membered ring comprising 0-3 double    bonds and 0-3 heteroatoms selected from O, N, Se or S wherein said    4-8 membered ring is optionally substituted with 1-3 groups    comprising C₁-C₁₈-alkyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆    alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂,    CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆    alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl and    heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)];-   X is Br or I;-   m is an integer between 1-50; and-   n is an integer between 1-50;

In one embodiment, this invention provides an oligofuran of formulaIII(m+2n) prepared by the process described herein above. In anotherembodiment, this invention provides an oligofuran of formula III(n+2m)prepared by the process described herein above.

In one embodiment, this invention provides an oligofuran of formulaIV(m+2n) prepared by the process described herein above. In anotherembodiment, this invention provides an oligofuran of formula IV(n+2m)prepared by the process described herein above.

In another embodiment this invention provide an oligofuran representedby the structure of formula I:

wherein X is Br or I; andn is between 1-20.

In another embodiment this invention provide an oligofuran representedby the structure of formula II:

wherein m is between 1-20.

In another embodiment this invention provide an oligofuran representedby the structure of formula V:

wherein X is Br or I;n is between 1-50;and R₁ and R₂ are as described for formula IV.

In another embodiment this invention provide an oligofuran representedby the structure of formula VI:

wherein m is between 1-50 and R₁, R₂ and R₃ are as described for formulaIV.

In another embodiment this invention provide an oligfuran represented bythe structure of formula VII:

wherein X is Br or I; andn is between 1-20.

In another embodiment this invention provide an oligfuran represented bythe structure of formula VIII:

wherein m is between 1-20.

In another embodiment this invention provide an oligfuran represented bythe structure of formula VIII:

wherein X is Br or I;m is between 1-50 and R₁, R₂ and R₃ are as described for formula IV.

In another embodiment this invention provide an oligfuran represented bythe structure of formula X:

wherein m is between 1-50 and R₁ and R₂ are as described for formula IV.

In another embodiment this invention provide an oligfuran represented bythe structure of formula XI:

wherein n is between 4-50; and

-   R is linear or branched C₁-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈    alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl,    (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH,    NH₂, NO₂, halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈    alkyl), NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈    alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈    alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or    heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl    groups are optionally substituted with 1-3 groups comprising halide,    [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl),    O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆alkyl)    or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)].

In another embodiment this invention provide an oligfuran represented bythe structure of formula XII:

-   wherein n is between 4-50; and R and R′ are independently hydrogen,    linear or branched C₁-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl,    (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl, (C₀-C₁₈    alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂,    halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl),    NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈    alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈    alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or    heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl    groups are optionally substituted with 1-3 groups comprising halide,    [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl),    O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆alkyl)    or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)].

In one embodiment R and/or R′ of formula XI and XII is a linear orbranched alkyl. In another embodiment R and/or R′ of formula XI and XIIis a haloakyl. In another embodiment R and/or R′ of formula XI and XIIis ethyl hexyl. In another embodiment R and/or R′ of formula XI and XIIis hexyl. In another embodiment R and/or R′ of formula XI and XII ismethyl. In another embodiment R and/or R′ of formula XI and XII is anaryl. In another embodiment R and/or R′ of formula XI and XII is aphenyl. In another embodiment R and/or R′ of formula XI and XII is anhalo-aryl. In another embodiment R and/or R′ of formula XI and XII is analkyl-phenyl. In another embodiment R and/or R′ of formula XI and XII isan alkyl-halophenyl. In another embodiment R and/or R′ of formula XI andXII is pentafluorobenzene. In another embodiment R and/or R′ of formulaXI and XII is aklkyl-pentafluorobenzene. In another embodiment R and/orR′ of formula XI and XII is an alkyl-phenyl wherein the phenyl issubstituted with between 1-5 fluoro groups. In another embodiment Rand/or R′ of formula XI and XII is an aryl wherein the aryl issubstituted with between 1-5 fluoro groups. In another embodiment, thesynthesis of exemplified oligofuran of formula XII is depicted in FIG.20.

In another embodiment this invention provide an oligfuran represented bythe structure of formula XIII:

-   wherein R₁, R₁′, R₁″, R₂, R₂′, R₂″, R₃ and R₄ are independently    hydrogen, C₁-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆    alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl, (C₀-C₁₈    alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂,    halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₁-C₁₈ alkyl), S—(C₁-C₁₈ alkyl),    NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈    alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈    alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or    heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl    groups are optionally substituted with 1-3 groups comprising halide,    [C₁-C₆ alkyl], CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl),    O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆    alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)];-   or-   R₁ and R₂; R₁′ and R₂′; R₁″ and R₂″ combine to form a 4-8 membered    ring comprising 0-3 double bonds and 0-3 heteroatoms selected from    O, N, Se or S wherein said 4-8 membered ring is optionally    substituted with 1-3 groups comprising C₁-C₁₈-alkyl, (C₀-C₆    alkyl)-cycloalkyl, (C₀-C₆ alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or    N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl    and heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆    alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally    substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN,    CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆    alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆    alkyl)][C(O)(C₁-C₆ alkyl)];-   m is an integer between 1-50;-   m′ is an integer between 0-50 and-   n is an integer between 1-50;    wherein if R₁, R₁′, R₁″ and R₂, R₂′, R₂″ are hydrogens then [n+m+m]    is not 3 or 4.

In one embodiment, R₁, R₁′, R₁″ and R₂, R₂′, R₂″ of the oligomer offormula XIII are the same. In another embodiment R₁, R₁′, R₁″ and R₂,R₂′, R₂″ of the oligomer of formula XIII are different. In anotherembodiment R₁, R₁′, R₁″ of formula XIII is hydrogen. In anotherembodiment R₂, R₂′, R₂″ of formula XIII is hydrogen. In anotherembodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently an alkyl. In another embodiment R₁, R₁′, R₁″, R₂, R₂′ andR₂″ of formula XIII are independently hydroxyalkyl. In anotherembodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently halo-alkyl. In another embodiment R₁, R₁′, R₁″, R₂, R₂′and R₂″ of formula XIII are independently alkyl-aryl. In anotherembodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently cycloalkyl, hetrocycloalkyl, aryl, or heteroaryl. In oneembodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently a linear or branched alkyl. In another embodiment R₁, R₁′,R₁″, R₂, R₂′ and R₂″ of formula XIII are independently a haloakyl. Inanother embodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently ethyl hexyl. In another embodiment R₁, R₁′, R₁″, R₂, R₂′and R₂″ of formula XIII are independently hexyl. In another embodimentR₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII are independently methyl.In another embodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently an aryl. In another embodiment In another embodiment R₁,R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII are independently phenyl. Inanother embodiment In another embodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″of formula XIII are independently halo-aryl. In another embodiment Inanother embodiment R₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII areindependently alkyl-phenyl. In another embodiment In another embodimentR₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII are independentlyalkyl-halophenyl. In another embodiment In another embodiment R₁, R₁′,R₁″, R₂, R₂′ and R₂″ of formula XIII are independentlypentafluorobenzene. In another embodiment In another embodiment R₁, R₁′,R₁″, R₂, R₂′ and R₂″ of formula XIII are independentlyaklkyl-pentafluorobenzene. In another embodiment In another embodimentR₁, R₁′, R₁″, R₂, R₂′ and R₂″ of formula XIII are independently analkyl-phenyl wherein the phenyl is substituted with between 1-5 fluorogroups. In another embodiment In another embodiment R₁, R₁′, R₁″, R₂,R₂′ and R₂″ of formula XIII are independently aryl wherein the aryl issubstituted with between 1-5 fluoro groups. In another embodiment, thesynthesis of exemplified oligofuran of formula XII is depicted in FIG.19.

In one embodiment, the oligofuran of formula XIII comprises a furanrepeating units, wherein only between 10-50% of the repeating units aresubstituted. In another embodiment between 10-50% of the repeating unitsare mono-substituted. In another embodiment between 10-50% of therepeating units are di-substituted. In another embodiment at least oneof the repeating units is mono or di-substituted.

In one embodiment, R₃ and R₄ of the oligomer of formula XIII are thesame. In another embodiment R₃ and R₄ of the oligomer of formula XIIIare different. In another embodiment R₃ of formula IV is hydrogen. Inanother embodiment R₄ of formula XIII is hydrogen. In another embodimentR₃ and R₄ of formula XIII are hydrogens. In another embodiment R₃ and R₄are not hydrogens. In another embodiment R₃ of formula XIII is an alkyl.In another embodiment R₄ of formula XIII is an alkyl. In anotherembodiment R₃ and R₄ are an alkyl. In another embodiment R₃ and R₃ areO-alkyl. In another embodiment R₃ and R₄ are methoxy group. In anotherembodiment R₃ and R₄ are hexyl. In another embodiment R₃ and R₄ aremethoxy group. In another embodiment R₃ and R₄ are methyl. In anotherembodiment R₃ and R₄ are methoxy group. In another embodiment R₃ and R₄are ethyl-hexyl. In another embodiment R₃ and R₄ are alkyl-phenyl; Inanother embodiment R₃ and R₄ are alkyl-pentafluorophenyl. In anotherembodiment R₃ and R₄ are alkyl-fluorophenyl; In another embodiment R₃and R₄ of formula XIII are independently hydroxyalkyl; In anotherembodiment R₃ and R₄ of formula XIII are independently halo-alkyl. Inanother embodiment R₃ and R₄ of formula XIII are independentlyalkyl-aryl; In another embodiment R₃ and R₄ of formula XIII areindependently cycloalkyl, hetrocycloalkyl, aryl, or heteroaryl.

In one embodiment, an oligomer of formula XIII is represented by thefollowing structure:

In one embodiment, an oligomer of formula XIII is represented by thefollowing structure:

In another embodiment, the synthesis of the above structures(3″-octyl-5F and 4″-hexyl-7F) is depicted in FIG. 19.

In one embodiment [n] of the oligomers of this invention is an integerbetween 1-20. In another embodiment, [n] of the oligomers of thisinvention is an integer between 1-50. In another embodiment, [n] of theoligomers of this invention is an integer between 1-10. In anotherembodiment, [n] of the oligomers of this invention is an integer between1-5. In another embodiment, [n] of the oligomers of this invention is aninteger between 5-10. In another embodiment, [n] of the oligomers ofthis invention is an integer between 20-30. In another embodiment, [n]of the oligomers of this invention is an integer between 25-50.

In one embodiment [m] of the oligomers of this invention is an integerbetween 1-20. In another embodiment, [m] of the oligomers of thisinvention is an integer between 1-50. In another embodiment, [m] of theoligomers of this invention is an integer between 1-10. In anotherembodiment, [m] of the oligomers of this invention is an integer between1-5. In another embodiment, [m] of the oligomers of this invention is aninteger between 5-10. In another embodiment, [n] of the oligomers ofthis invention is an integer between 20-30. In another embodiment, [n]of the oligomers of this invention is an integer between 25-50.

In another embodiment, the oligofurans of this invention comprise 5repeating units. In one embodiment, the oligofurans of this inventioncomprise 6 repeating units. In one embodiment, the oligofurans of thisinvention comprise 7 repeating units. In one embodiment, the oligofuransof this invention comprise 8 repeating units. In one embodiment, theoligofurans of this invention comprise 9 repeating units. In oneembodiment, the oligofurans of this invention comprise 10 repeatingunits. In one embodiment, the oligofurans of this invention comprisebetween 5-10 repeating units. In one embodiment, the oligofurans of thisinvention comprise between 5-15 repeating units. In one embodiment, theoligofurans of this invention comprise between 5-20 repeating units. Inone embodiment, the oligofurans of this invention comprise between 5-30repeating units. In one embodiment, the oligofurans of this inventioncomprise between 4-50 repeating units. In one embodiment, theoligofurans of this invention comprise between 10-15 repeating units. Inone embodiment, the oligofurans of this invention comprise between 15-20repeating units. In one embodiment, the oligofurans of this inventioncomprise between 20-25 repeating units. In one embodiment, theoligofurans of this invention comprise between 25-30 repeating units. Inone embodiment, the oligofurans of this invention comprise between 30-40repeating units. In one embodiment, the oligofurans of this inventioncomprise between 40-50 repeating units. In one embodiment, theoligofurans of this invention comprise between 50-60 repeating units. Inone embodiment, the oligofurans of this invention comprise between 50-80repeating units. In one embodiment, the oligofurans of this inventioncomprise between 80-100 repeating units. In one embodiment, theoligofurans of this invention comprise between 100-150 repeating units.

In one embodiment, the oligofurans of this invention comprisemono-substitutred or bis-substituted repeating units of furan. Inanother embodiment, only between 10-50% of the furan repeating units aremono-substituted or bis-substituted. In another embodiment, 100% of thefuran repeating units are mono-substituted or bis-substituted. Inanother embodiment, at least one of the furan repeating units ismono-substituted or bis-substituted.

An “alkyl” group refers, in one embodiment, to a saturated aliphatichydrocarbon, including straight-chain, branched-chain and cyclic alkylgroups. In one embodiment, the alkyl group has 1-25 carbons. In oneembodiment, the alkyl group has 1-18 carbons. In one embodiment, thealkyl group has 1-12 carbons. In one embodiment, the alkyl group has1-15 carbons. In another embodiment, the alkyl group has 1-7 carbons. Inone embodiment the alkyl in n-hexyl. In one embodiment the alkyl ismethyl. In one embodiment the alkyl in n-octyl. In another embodiment,the alkyl group has 1-6 carbons. In another embodiment, the alkyl grouphas 1-4 carbons. The alkyl group may be unsubstituted or substituted byone or more groups selected from halogen, hydroxy, alkoxy carbonyl,amido, alkylamido, dialkylamido, nitro, amino, alkylamino, dialkylamino,carboxyl, thio and thioalkyl.

A “haloalkyl” group refers to an alkyl group as defined above, which issubstituted by one or more halogen atoms, in one embodiment by F, inanother embodiment by Cl, in another embodiment by Br, in anotherembodiment by I.

A “hydroxyalkyl” group refers to an alkyl group as defined above, whichis substituted by one or hydroxyl groups.

A “cycloalkyl” group refers to a cyclic group having at least onesaturated carbocyclic group which may be unsubstituted or substituted byone or more groups selected from halogen, haloalkyl, hydroxy, alkoxy,carbonyl, amido, alkylamido, dialkylamido, nitro, amino, alkylamino,dialkylamino, carboxy or thio or thioalkyl. Nonlimiting examples ofcycloalkyl rings are cyclopropane, cyclobutane, cyclopentane,cyclohexane, cycloheptane, cyclooctane, and the like. In one embodiment,the cycloalkyl group is a 3-12 membered ring. In another embodiment, thecycloalkyl group is a 3-8 membered ring. In another embodiment, thecycloalkyl group comprises of 1-4 fused rings.

An “aryl” group refers to an aromatic group having at least onecarbocyclic aromatic group or heterocyclic aromatic group, which may beunsubstituted or substituted by one or more groups selected fromhalogen, haloalkyl, hydroxy, alkoxy, carbonyl, amido, alkylamido,dialkylamido, nitro, amino, alkylamino, dialkylamino, carboxy or thio orthioalkyl. Nonlimiting examples of aryl rings are phenyl, naphthyl,pyranyl, pyrrolyl, pyrazinyl, pyrimidinyl, pyrazolyl, pyridinyl,furanyl, thiophenyl, thiazolyl, imidazolyl, isoxazolyl, quinolyl,isoquinolyl, and the like. In one embodiment, the aryl group is a 3-12membered ring. In another embodiment, the aryl group is a 3-8 memberedring. In another embodiment, the aryl group comprises 3-4 fused rings

A “hydroxyl” group refers to an OH group.

The term “halogen” refers to in one embodiment to F, in anotherembodiment to Cl, in another embodiment to Br, in another embodiment toI.

The term “ring” refers to a monocyclic or bicyclic aromatic or aliphaticring system comprising 3-10 atoms. In one embodiment, said ring contains0-4 heteroatoms selected from O, N and S. In another embodiment, saidring is optionally substituted with 0-3 groups. In another embodiment,said ring is cyclohexane. In another embodiment, said ring iscyclopentane. In another embodiment, said ring is benzene. In anotherembodiment, said ring is naphthalene. In another embodiment, said ringis piperazine. In another embodiment, said ring is quinoline.

A “heterocycle” group refers, in one embodiment, to a ring structurecomprising in addition to carbon atoms, sulfur, oxygen, nitrogen or anycombination thereof, as part of the ring. In another embodiment theheterocycle is a 3-12 membered ring. In another embodiment theheterocycle is a 6 membered ring. In another embodiment the heterocycleis a 5-7 membered ring. In another embodiment the heterocycle is a 4-8membered ring. In another embodiment, the heterocycle group may beunsubstituted or substituted by a halogen, haloalkyl, hydroxyl, alkoxy,carbonyl, amido, alkylamido, dialkylamido, cyano, nitro, CO₂H, amino,alkylamino, dialkylamino, carboxyl, thio and/or thioalkyl. In anotherembodiment, the heterocycle ring may be fused to another saturated orunsaturated cycloalkyl or heterocyclic 3-8 membered ring. In anotherembodiment, the heterocyclic ring is a saturated ring. In anotherembodiment, the heterocyclic ring is an unsaturated ring.

The term “substituted” refers to substitution of one or more hydrogenswith non-hydrogen groups. Non-limiting examples of non-hydrogen groupsincludes alkyl, alkenyl, alkynyl, haloalkyl, aryl, hydroxyl, alkoxyl,cyano, amido, carboxyl, amino, halogen, etc.

An “alkenyl” group refers, in another embodiment, to an unsaturatedhydrocarbon, including straight chain, branched chain and cyclic groupshaving one or more double bond. The alkenyl group may have one doublebond, two double bonds, three double bonds etc. Examples of alkenylgroups are ethenyl, propenyl, butenyl, cyclohexenyl etc. The alkenylgroup may be unsubstituted or substituted by one or more groups selectedfrom halogen, hydroxy, alkoxy carbonyl, amido, alkylamido, dialkylamido,nitro, amino, alkylamino, dialkylamino, carboxyl, thio and thioalkyl.

An “alkynyl” group refers, in another embodiment, to an unsaturatedhydrocarbon, including straight chain, branched chain and cyclic groupshaving one or more triple bond. The alkynyl group may have one triplebond, two triple bonds, three triple bonds etc. Examples of alkynylgroups are ethynyl, propynyl, butynyl, etc. The alkynyl group may beunsubstituted or substituted by one or more groups selected fromhalogen, hydroxy, alkoxy carbonyl, amido, alkylamido, dialkylamido,nitro, amino, alkylamino, dialkylamino, carboxyl, thio and thioalkyl.

In one embodiment, this invention provides a process for the preparationof polyfuran of formula III comprising:

-   (a) brominating oligofuran of formula III(m+2n) or oligofuran of    formula III(n+2m) to yield the corresponding 2,5-dibromo-oligofuran    or 2-bromo-oligofuran;-   (b) reacting oligofuran of formula III(m+2n) or oligofuran of    formula III(n+2m) with tributyltin chloride to yield the    corresponding 2-tributyltin-oligofuran or    2,5-bis(tributyl)tin-oligofuran;-   (c) reacting 2,5-dibromo-oligofuran or 2-bromo-oligofuran of    step (a) with 2-tributyltin-oligofuran or    2,5-bis(tributyl)tin-oligofuran of step (b) in the presence of    tetrakis(triphenylphosphine)palladium Pd(PPh₃)₄ to yield a polyfuran    chain of formula III.

In another embodiment, steps (a-c) are repeated to obtain a longer chainof polyfuran of formula III.

In one embodiment, this invention provides a process for the preparationof polyfuran of formula IV comprising:

-   (a) brominating oligofuran of formula IV(m+2n) or oligofuran of    formula IV(n+2m) to yield the corresponding 2,5-dibromo-oligofuran    or 2-bromo-oligofuran;-   (b) reacting oligofuran of formula IV(m+2n) or oligofuran of formula    IV(n+2m) with tributyltin chloride to yield the corresponding    2-tributyltin-oligofuran or 2,5-bis(tributyl)tin-oligofuran;-   (c) reacting 2,5-dibromo-oligofuran or 2-bromo-oligofuran of    step (a) with 2-tributyltin-oligofuran or    2,5-bis(tributyl)tin-oligofuran of step (b) in the presence of    tetrakis(triphenylphosphine)palladium Pd(PPh₃)₄ to yield a polyfuran    chain of formula IV.

In another embodiment, steps (a-c) are repeated to obtain a longer chainof polyfuran of formula IV.

In another embodiment 2,5-dibromo-oligofuran reacts with2-tributyltin-oligofuran. In another embodiment, 2-bromo-oligofuranreacts with 2,5-bis(tributyl)tin-oligofuran. In another embodiment,2,5-bis(tributyl)tin-oligofuran reacts with 2,5-dibromo-oligofuran.

In one embodiment, this invention provides a polyfuran or oligofuran offormula III or IV prepared according to the process described in thisinvention. In one embodiment, this invention provides a polyfuran oroligofuran of formula III or IV prepared according to the processdescribed in this invention.

In one embodiment, the process of this invention for the preparation ofoligofuran or polyfuran of formula III or IV comprising reacting a 2,5dibromo-oligofuran or 2-bromo-oligofuran with 2-tributyltin oligofuranor 2,5-bis(tributyl)tin-oligofuran. In another embodiment, the reactionis in the presence of tetrakis(triphenylphosphine)palladium [Pd(PPh₃)₄].

In one embodiment, this invention provides a process for the preparationof oligofuran or polyfuran, wherein 2,5-dibromo-oligofuran or2-bromo-oligofuran is one of the reactants. In another embodiment, the2,5-dibromo-oligofuran or 2-bromo-oligofuran is prepared by brominationof the corresponding oligofuran.

In another embodiment, the bromination is in the presence ofN-bromosuccinimide (NBS). In another embodiment, the bromination isaccording to Fumio et al., Bull. Chem. Soc. Jpn. 63, 2828 (1990), whichis incorporated herein by reference.

In one embodiment, this invention provides a process for the preparationof polyfuran of formula III comprising:

-   (a) iodination of oligofuran of formula III(m+2n) or oligofuran of    formula III(n+2m) to yield the corresponding 2,5-diiodo-oligofuran    or 2-iodo-oligofuran;-   (b) reaction of oligofuran of formula III(m+2n) or oligofuran of    formula III(n+2m) with tributyltin chloride to yield the    corresponding 2-tributyltin-oligofuran or    2,5-bis(tributyl)tin-oligofuran;-   (c) reacting 2,5-diiodo-oligofuran or 2-iodo-oligofuran of step (a)    with 2-tributyltin-oligofuran or 2,5-bis(tributyl)tin-oligofuran of    step (b) in the presence of tetrakis(triphenylphosphine)palladium    Pd(PPh₃)₄ to yield a polyfuran chain of formula III.

In another embodiment, steps (a-c) are repeated to obtain a longer chainof polyfuran of formula III.

In one embodiment, this invention provides a process for the preparationof polyfuran of formula IV comprising:

-   (a) iodination of oligofuran of formula IV(m+2n) or oligofuran of    formula IV(n+2m) to yield the corresponding 2,5-diiodo-oligofuran or    2-iodo-oligofuran;-   (b) reacting oligofuran of formula IV(m+2n) or oligofuran of formula    IV(n+2m) with tributyltin chloride to yield the corresponding    2-tributyltin-oligofuran or 2,5-bis(tributyltin-oligofuran;-   (c) reacting 2,5-diiodo-oligofuran or 2-iodo-oligofuran of step (a)    with 2-tributyltin-oligofuran or 2,5-bis(tributyl)tin-oligofuran of    step (b) in the presence of tetrakis(triphenylphosphine)palladium    Pd(PPh₃)₄ to yield a polyfuran chain of formula IV.

In another embodiment, steps (a-c) are repeated to obtain a longer chainof polyfuran of formula IV.

In another embodiment 2,5-diiodo-oligofuran reacts with2-tributyltin-oligofuran. In another embodiment, 2-iodo-oligofuranreacts with 2,5-bis(tributyl)tin-oligofuran. In another embodiment,2,5-bis(tributyl)tin-oligofuran reacts with 2,5-diiodo-oligofuran.

In one embodiment, this invention provides a polyfuran or oligofuran offormula III or IV prepared according to the process described in thisinvention. In one embodiment, this invention provides a polyfuran oroligofuran of formula III or IV prepared according to the processdescribed in this invention.

In one embodiment, the process of this invention for the preparation ofoligofuran or polyfuran of formula III or IV comprising reacting a 2,5diiodo-oligofuran or 2-iodo-oligofuran with 2-tributyltin oligofuran or2,5-bis(tributyl)tin-oligofuran. In another embodiment, the reaction isin the presence of tetrakis(triphenylphosphine)palladium [Pd(PPh₃)₄].

In one embodiment, this invention provides a process for the preparationof oligofuran or polyfuran, wherein 2,5-diiodo-oligofuran or2-iodo-oligofuran is one of the reactants. In another embodiment, the2,5-diiodo-oligofuran or 2-iodo-oligofuran is prepared by bromination ofthe corresponding oligofuran.

In one embodiment, this invention provides a process for the preparationof oligofuran or polyfuran, wherein 2-tributyltin-oligofuran or2,5-bis(tributyl)tin-oligofuran is one of the reactants. In anotherembodiment, 2-tributyltin-oligofuran or 2,5-bis(tributyl)tin-oligofuranis prepared by derivatizing the corresponding oligofuran withbutyllithium followed by tributylthin-chloride. In another embodiment,Stille coupling between tin-oligofurans and bromo-oligofurans oriodo-oligofuran is followed by reduced vacuum sublimation of thefiltrate to yield oligofuran.

In one embodiment, furans can be obtained from renewable resources. Inanother embodiment, the oligofurans of this invention are biodegradable.In another embodiment, this invention is directed to biodegradableoligofuran based on renewable resources.

In one embodiment, furan can be prepared from renewable sources of mono,oligo and polysaccharides such as cellulose polymer, glucose, fructose,corn cobs, oat, rice hulls, sugarcane, cotton seeds, olive husks andstones. The reaction sequence leading to furan first goes throughacid-catalyzed hydrolysis of the polymeric pentoses or hexoses to thecorresponding monosaccharide, followed by acid-catalyzed dehydration,and finally cyclization to give furan which can be used for polymersyntheses. In another embodiment, lignocellulosic biomass is a renewableresource for fuels and chemicals (such as furan) by using N,Ndimethylacetamide (DMA) and lithium chloride (LiCl) through catalysis byBronsted acids. (e.g. H₂SO₄) as described in Joseph B. Binder and RonaldT Raines, JACS, 2009, 131, 1979-1985, which is incorporated herein byreference.

In one embodiment, the oligofuran of this invention is biodegradable. Inanother embodiment, the oligofuran of this invention degradeenzymatically using lipase including non limiting examples as Porcinepancreas, Rhizopus Delmar or Pseudomonas sp. In another embodiment, theoligofuran of this invention is biodegradable by soil burial. In anotherembodiment, a bacteria and/or a fungi are mainly responsible for thedegradation by soil burial.

Enzymatic degradability is evaluated by the measurement of total organiccarbon content (TOC) of aqueous solutions containing water-solubledegradation products.

Conjugated compounds, inherently possess low solubility. For manyindustrial applications processability from solution and thereforesolubility is an essential requirement if an economically viable processis to be obtained. Therefore in one embodiment, the process of thisinvention provides oligofurans, with higher solubility compared forexample to corresponding oligothiophenes that improves the ease ofprocessability, and enables drop casting/spin casting techniques to beused. (the solubility of 6F is 0.7 mg/mL compared to only <0.05 mg/mLfor 6T-oligothiophene possessing 6 units) In another embodiment thesubstituted oligofurans of this invention (Oligofuran IV, IV-A, DH-6F,V, VI, IX, X, XI, XII and XIII) are more soluble than the unsubstitutedoligomers of this invention. In another embodiment, R₁ and R₂ ofoligofurans IV, V, VI, 1× and X increase the solubility of theoligofurans of this invention. In another embodiment R, R′, R₁, R₁′,R₁″, R₂, R₂′, R₂″ of oligofurans IV, IV-A, V, VI, IX, X, XI, XII andXIII improve the electronic properties of the oligofuran. In anotherembodiment R, R′, R₁, R₁′, R₁″, R₂, R₂′, R₂″ of oligofurans IV, IV-A, V,VI, IX, X, XI, XII and XIII improve the stability properties of theoligofuran.

In another embodiment, the oligofurans, polyfurans and copolymersprepared according to the process of this invention provide higherfluorescence and better packing (i.e shorter interplane distances) thanthe corresponding oligothiophenes.

In one embodiment, the oligofuran and polyfuran of this inventionprovide an efficient charge transport material (e.g., for OFETs) and asa luminescent material for organic light emission devices (OLEDs andOLETs). These advantages, as compared mainly to oligothiophenes (OTs),include: (i) higher fluorescence quantum yield (up to 75%), (ii) highrigidity and high planarity; (iii) high rigidity and high planarity,(iv) high charge mobility (v) better solubility compared to thecorresponding oligothiophenes (Table 1) and (vi) Furan-containingpolymers are biodegradable

In one embodiment, the oligofuran and polyfuran of this inventionprovide higher fluorescence quantum yield than the correspondingoligothiophenes. Short OFs show a high fluorescent quantum yield in thedeep blue spectral region that is very challenging for efficientelectroluminescent devices.

In one embodiment, the oligofuran and polyfuran of this inventionprovide high rigidity and high planarity than the correspondingoligothiophenes. Oligofurans are significantly more rigid thanoligothiophenes (FIG. 16). The high rigidity of OFs is seen in theirsignificantly lower Stokes shift (around 0.25 eV for 3F-9F, and around0.40 eV for 3T-6T, Table 1). Second, the optical absorption spectra ofOFs in solution show a vibrational structure that is typically absent inOTs. The energy required to twist 6F is significantly greater than for6T. Moreover, the high planarity is expected to facilitate densesolid-state packing that should result in good overlapping of molecularn-orbitals and hence enhanced charge transport properties. In oneembodiment, the oligofuran of this invention maintain planarity betterthan oligothiophenes. In another embodiment, the X-ray structure of 6Fi.e possessing 6 repeat units of furan) shows the oligomers to becompletely planar, with herringbone packing, as for α-sexithiophene(6T), as presented in FIG. 7. The intermolecular distances are shortercompared to 6T. The distance between planes is 2.57 Å in 6F, which issignificantly shorter than in 6T (2.89 Å), providing possible bettercharge mobility. Also the molecular density (obtained by dividing thenumber of molecules per unit cell volume) is 17% higher in 6F(oligofuran possessing six furan units) than in 6T (oligothiophenepossessing six thiophene groups). In another embodiment, unlikethiophene analogues, 3F and 4F packing is not a herringbone.

In one embodiment, the oligofuran and polyfuran of this inventionprovide High charge mobility than the corresponding oligothiophenes. AsOFs are more electron-rich and planar than OTs, one can expect OFs tohave the potential to be good charge transport materials. Achievement ofsignificant field effect mobility in oligofurans paves the way for theirapplication in different devices based on nano-materials, such as OFETs,OLETs, and sensors. Therefore, oligofuran-based nanomaterials may bevery promising, for example, for hole conduction.

In one embodiment, the oligofuran and polyfuran of this inventionprovide better solubility than the corresponding oligothiophenes.Solubility is among the key technological demands placed on materialsfor high-scale organic electronic nanotechnologies. Furans are more thanan order of magnitude more soluble in common organic solvents thanthiophenes, which allows unsubstituted furans to be processed fromsolution (e.g., by spin/drop/dip coating techniques). In addition,longer furans can be synthesized. This allows a greater variety ofoligomers, with different emission wavelengths (from 350 nm for 3F up to473 nm for 9F), allowing fine tuning of the solution emission spectrafrom the blue to green regions. In one embodiment, the solubility of theoligofuran of this invention is greater than the correspondingoligothiophenes. In another embodiment, oligofuran 6F (i.e possessing 6repeat units of furan) in chloroform is over 10 times more soluble thanthe corresponding 6T (i.e possessing 6 repeat units of thiophene): 0.7mg/mL compared to <0.05 mg/mL for 6T.

In one embodiment, the oligofuran and polyfuran of this invention arebiodegradable, in contrast to their thiophene analogs and furans can beobtained from renewable resources, unlike other organic electronicmaterials.

In one embodiment, this invention provides oligofurans and polyfuranswhich are stable in air. In another embodiment, oligofuran 6F (i.epossessing 6 repeat units) is stable in air in the absent of light,demonstrating decomposition only at 303° C. as presented in FIG. 3. Inanother embodiment, the oligofurans and polyfurans of this invention arestable in the solid state. X-ray crystallographic analysis revealed aherringbone molecular packing in the solid state tighter than thatobserved for thiophenes.

In one embodiment, the oligofurans and polyfurans of this inventioncopolymerise with other polymerisable heterocyclic compounds, orunsaturated systems, such as for example with pyrrole, thiophene,aromatics, alkyne, substituted furan or any combination thereof.

In another embodiment, the alkyne is acetylene, dialkynes, polyalkynes,alkenylalkynes halogen-substituted acetylenes, arylacetylenes, oralkylacetylenes. In another embodiment, the alkyl comprises between 1 to25 carbon atoms. In another embodiment, the alkyl comprises between 1 to18 carbon atoms. In another embodiment, the alkyl comprises between 1 to12 carbon atoms. Examples of alkylacetylenes are propyne, butyne,pentyne, hexyne, heptyne, octyne and decyne. In another embodiment, thearylacetylene is phenylacetylene. In another embodiment the dialkynesand polyalkynes comprise butadiyne, hexadiyne, octadiyne,diethynylbenzene and triethynylbenzene.

In another embodiment, the aromatics are linear fused polynucleararomatics, such as anthracene, tetracene or pentacene. In anotherembodiment, the aromatics comprise a phenyl group.

In one embodiment, the oligofuran and polyfuran of this invention is anunsubstituted furan. In another embodiment, the furan itself issubstituted. In another embodiment, the substituted furan isN-alkylfuran, N-arylfuran, alkyl-substituted furan, halogenated-furan.In the preparation of the copolymers, the furan can be used alone ormixed with one another, so that the copolymers may contain one or moredifferent furans. In another embodiment, the repeating furan units inthe copolymers are essentially based on unsubstituted furan itself.

In one embodiment, this invention provides a process for the preparationof a copolymer comprising furan and the monomer to be polymerized with;comprising reacting 2,5-dibromo-oligofuran of formula I(as describedabove) with monosubstituted tri-butyltin oligomer. In anotherembodiment, the reaction between the 2,5-dibromo-oligofuran andmonosubstituted tri-butyltin olygomer is in the presence of Pd(PPh₃)₄.In another embodiment, the monosubstituted tri-butyltin oligomer refersto an oligomer having one end group of hydrogen and the other end groupof tri-butyltin. In another embodiment, the oligomer comprises pyrrole,thiophene, aromatics, alkyne, substituted furan or any combinationthereof. In another embodiment, the tributyltin end group is in alphaposition of pyrrole or thiophene.

In one embodiment, this invention provides a process for the preparationof a copolymer comprising furan and the monomer to be polymerized with;comprising reacting dibromo-oligomer with 2-tributyltin oligofuran offormula II. In another embodiment, the reaction between thedibromo-oligomer and the 2-tributyltin oligofuran (II) is in thepresence of Pd (PPh₃)₄. In another embodiment, the dibromo oligomerrefers to an oligomer having two end groups of bromine. In anotherembodiment, the oligomer comprises pyrrole, thiophene, aromatics,alkyne, substituted furan or any combination thereof.

In one embodiment, this invention provides a process for the preparationof copolymers comprising furan and thiophene as monomers. In anotherembodiment, this invention provides a process for the preparation ofcopolymers comprising furan and pyrrole as monomers. In anotherembodiment, this invention provides a process for the preparation ofcopolymer comprising furan and phenyl as monomers. In anotherembodiment, this invention provides a process for the preparation ofcopolymer comprising furan and alkyne as monomers.

In one embodiment, this invention provides a copolymer which is preparedaccording to the process of this invention comprising furan andsubstituted furan as monomers. In another embodiment, this inventionprovides a copolymer which is prepared according to the process of thisinvention comprising furan or substituted furan with pyrrole orsubstituted pyrrole as monomers. In another embodiment, this inventionprovides a copolymer which is prepared according to the process of thisinvention comprising furan or substituted furan with thiophene orsubstituted thiophene as monomers. In another embodiment, this inventionprovides a copolymer which is prepared according to the process of thisinvention comprising furan or substituted furan with phenyl orsubstituted phenyl as monomers. In another embodiment, this inventionprovides a copolymer which is prepared according to the process of thisinvention comprising furan or substituted furan with alkyne orsubstituted alkyne as monomers.

In one embodiment, the substituted pyrrole, thiophene, phenyl or alkyneinclude an alkyl (having 1-18 carbons), phenyl, amine, amide, halogen,hydroxyl, SH, CN, NO₂ or COOH groups.

In another embodiment, the proportion of the polyfuran or oligofuran andthe monomers to be polymerised can vary within wide limits, depending onthe specific type of copolymer, and its intended properties; forexample, it can be from 1 to 99% by weight of total weight of themonomers to be polymerised (the percentage by weight is based on thetotal weight of the monomers to be polymerised). In another embodiment,the ratio of the oligofuran or polyfuran and the monomers to bepolymerized is between 20:80 to 90:10.

Methods of Use.

In some embodiments of this invention the polyfurans, oligofurans andcopolymers prepared by the processes of this invention can be used forthe production of electrodes, catalysts, electrical storage systems,shielding materials, fluorescent markers, dyes, pigments, electricalswitches, semiconductor components, electrochromic materials,electromagnetic interference materials, electro-optical devices such aslight emitting diodes, field-effect transistors, solar cells, polarizingoptical elements and batteries or for the antistatic treatment ofplastics.

In one embodiment, this invention provides the use of the oligofuran,polyfuran and copolymer of this invention for imparting antistaticproperties on plastic films. In another embodiment, imparting antistaticproperties on plastic films comprising a heat treatment of the coatedfilms with mechanical deformation of the films, wherein said filmscomprise of oligofuran, polyfuran or copolymer of this invention.Simultaneous heat treatment and mechanical deformation of this typetakes place in the production of plastic moldings from plastic films bythermoforming the films.

In one embodiment, this invention provides film coatings or layers ofthe oligofuran, polyfuran or copolymer of this invention in conjunctionwith a substrate. In another embodiment, non limiting examples ofsubstrate includes a metal foil, a graphite, gold, silicon, glass, asemiconductor, titanium.

In another embodiment, the oligofurans of this invention are highlyfluorescent, and can be used as fluorescent materials, markers, fieldeffect transistors embedded in polymer matrices such as PMMA (polymethylmethacrylate).

In one embodiment, the oligomers of this invention are fluorescent. Inanother embodiment, oligofuran IV-B (DH-6F) is fluorescent, with quantumyield of 72%, and with a melting temperature lower than that of 6F (231°C. and 260° C., respectively, see FIG. 10) for DSC traces). In anotherembodiment, the oligofuran of this invention are thermally stable. Inanother embodiment, thermogravimetric analysis (TGA) for the oligofuransof this invention are thermally stable, with sublimation occurs prior todecomposition (FIG. 11).

In one embodiment, the end substitution with alkyl chains gives themolecules liquid-crystalline-like properties, which increases theordering and enhances the charge mobility of the resulting evaporatedfilms. In another embodiment, elongation of the chain length (i.eincrease in number of furan units) or introduction of long alkyl chainsleads to decrease of the HUMO-LUMO gap and leads to increase in chargecarrier mobility.

In one embodiment, the present invention can further include a method ofusing oligofuran or polyfuran structural modification to provide, p-typeconductivity

In one embodiment, the present invention can further include a method ofusing oligofuran or polyfuran structural modification to provide, n-typeconductivity. Such a method includes (1) preparing a elongatedoligofuran or polyfuran; (2) providing the oligofuran a structuralmodification sufficient to promote n-type conductivity, such amodification including but not limited to alkyl, fluoroalkylsubstitution, fluorine substitution, fluoroaryl insertion, heterocycleinsertion and combinations thereof. Alternatively, various synthetictechniques, depending upon the desired modification, can be madesubsequent thereto. Such modifications can provide a wide variety ofoligofuran compositions, such compositions including but not limited tothose embodiments discussed above.

In another embodiment, the oligomers of this invention is deposited onthe substrate by spin casting, drop casting, spraying, knife coating,brushing, subliming or printing.

In one embodiment, to increase or improve the electrical conductivity ofthe oligofuran, polyfuran or copolymer prepared according to theinvention, dopants are added.

In one embodiment, the oligofuran, polyfuran or copolymer of thisinvention comprise a dopant. In another embodiment, the dopant isp-type. In another embodiment, the p-type dopant is Br₃ ⁻, I₃ ⁻, AsF₆ ⁻,ClO₄ ⁻, BF₄ ⁻ or FeCl₄ ⁻. In another embodiment, the dopant is n-type.In another embodiment, the n-type dopant is Li⁺, Na⁺ or K⁺.

In one embodiment, conductive polyfuran/oligofuran/copolymer filmshaving holes (p-doped) can be formed via conventional p-dopants whichinclude halogen atoms, e.g., I₂, Cl₂, Br₂, ICl, ICl₃, IBr and IF, Lewisacids, e.g., PF₅, AsF₅, SbF₅, BF₃, BCl₃, SbCl₅, BBr₃ and SO₃, protonicacids, organic acids, or amino acids, e.g., HF, HCl, HNO₃, H₂SO₄, HClO₄,FSO₃H and ClSO₃H, transition metal compounds, e.g., FeCl₃, Fe(OCl)₃,Fe(ClO₄)₃, Fe(CH₃C₆H₄SO₃)₃, TiCl₄, ZrCl₄, HfCl₄, NbF₅, NbCl₅, TaCl₅,MoF₅, MoCl₅, WF₅, WCl₆, UF₆ and LnX₃ wherein Ln is a lanthanoid and X isan anion, e.g., Cl⁻, Br⁻, I⁻, I₃ ⁻, HSO₄ ⁻, SO₄ ²⁻, NO₃ ⁻, ClO₄ ⁻, BF₄⁻, B₁₂F₁₂ ²⁻, PF₆ ⁻, SbF₆ ⁻, FeCl₄ ⁻, Fe(CN)₆ ³⁻, and anions of varioussulfonic acids, such as aryl-SO₃ ⁻. Also, O₂, as well as O₃, may beused. Conductive polymeric films employing electrons as carriers as inn-doped polymeric films utilize conventional n-dopants which include thealkali metals (e.g., Li, Na, K, Rb, and Cs), alkaline-earth metals e.g.,Ca, Sr, and Ba.

In one embodiment, the polyfuran/oligofuran/copolymer of this inventionmay be doped with conventional p- and n-type dopants post polymerizationof the respective monomers. The doping process typically involvestreatment of the film material with an oxidizing or reducing agent in aredox reaction to form delocalized ionic centers in the material, withthe corresponding counterions derived from the applied dopants. Dopingmethods comprise for example exposure to a doping vapor in theatmospheric or at a reduced pressure, electrochemical doping in asolution containing a dopant, bringing the dopant in contact with thepolymer to be thermally diffused, and ion-implantantion of the dopantinto the semiconductor material.

The term “dopant” refers, in one embodiment to a substance which isadded to a polyfuran/copolymer in small quantities in order to cause themixture of polyfuran/copolymer and dopant to be electrically conductive.However, though these polyfuran/copolymer are electrically conductivewithout a dopant, the magnitude of the conductivity can be increased byadding a dopant material.

In one embodiment, the oligofuran, polyfuran and copolymer of thisinvention layers and/or composites for thin film deposition are usefulin conjunction with the fabrication of thin film transistors and relateddevices as can be incorporated into an integrated circuit.

In one embodiment, this invention provides a use of the oligofuran,polyfuran or copolymer of this invention as a field-effect active layerin a semiconductor device which is a field-effect transistor. Bydetermining current voltage characteristics at various gate voltages afield-effect is observed. A typical value of the field-effectcharge-carrier mobility is approximately 10⁻⁰-10⁻⁶ cm²/Vs) at a bulkconductivity. These values are typical of amorphous semiconductingpolymers processed from solution. A good field-effect transistorcombines a high mobility with a low bulk conductivity.

In one embodiment, this invention provides a semiconductor device havinga semiconducting layer comprising the formation of a layer by dropcasting, spin casting, spin spraying, sublimation, knife coating,brushing or printing (such as inkjet printing) using the oligofuran,polyfuran or copolymer of this invention.

Spin-coating is particularly suitable for devices wherein patterning ofthe electroluminescent material is unnecessary—for example for lightingapplications or simple monochrome segmented displays.

Inkjet printing is particularly suitable for high information contentdisplays, in particular full color displays. Inkjet printing of OLEDs isdescribed in, for example, EP 0880303, which is incorporated herein byreference.

In one embodiment, this invention provides a use of the oligofuran,polyfuran or copolymer of this invention as a coating layer of anelectrode. The coating thickness of the applied coating after drying isgenerally 0.1 to 100 μm, depending on the conductivity desired and onthe coating transparency desired.

In one embodiment, this invention provides a use oligofuran, polyfuranor copolymer of this invention as electrode material for rechargeablebatteries. In another embodiment the oligofuran, polyfuran or copolymerof this invention are stable when used as electrode material forrechargeable batteries having a lower rate of self-discharge and can bere- and discharged (i.e. cyclised) frequently.

In one embodiment, this invention provides an electrochromic devicecomprising polyfuran or copolymer of this invention.

In one embodiment, the term “electrochromic device” refers toelectrolytic cells that change their ability to transmit (or reflect)light in response to a small bias (typically 1-2 V) applied across thetwo electrodes.

In another embodiment, the electrochromic devices include displays,electronic ink, sensors, sun glasses, traffic signs or memory elements.

In one embodiment, this invention provides an organic light-emittingdevice, comprising: a first electrode; a second electrode; an emittinglayer interposed between the first electrode and the second electrode;and at least one of a hole transporting layer and a hole injecting layerinterposed between the emitting layer and the first electrode, said atleast one of the hole transporting layer and the hole injecting layerobtained from a said conducting polymer. In another embodiment thelayers are comprised of the polyfuran/oligofuran/copolymer of theinvention.

In one embodiment, there is provided an electrical device, for example,an opto-electronic device, comprising a conductivepolyfuran/oligofuran/copolymer of this invention as a charge injectinglayer in light emitting devices; as a component in electrochromicdisplays and as electrodes in field-effect transistors and asphotovoltaic cells as the alternative for ITO.

In one embodiment, there is provided an electrical device, for example,an opto-electronic device, comprising a conductive polyfuran/copolymerof this invention. In another embodiment, the electrical devicecomprises an anode, a cathode, and an organic semi-conductive layerbetween the anode and cathode. The conductive polyfuran/copolymer may beprovided in a layer between the anode and cathode. When the conductivepolyfuran/copolymer is used as a hole injection material, the layercomprising the conductive polymer is preferably located between theanode and the organic semi-conductive layer. When the conductive polymeris used as an electron transport material, the layer comprising theconductive polymer is preferably located between the cathode and theorganic semi-conductive layer or in the organic semi-conductive layer.The organic semi-conductive layer preferably is light-emissive. Theanode preferably comprises indium-tin-oxide (ITO).

In another embodiment, the devices of this invention comprising thepolyfuran, oligofuran or copolymer of this invention can be used in,e.g. imaging and electronics applications. In another embodiment, thedevices can be used as a field effect transistor, light emitting diode,light emitting transistors, photovoltaic cell, or as display backplanes.

A Light Emitting Transistor (LET) is a form of transistor that emitslight. Such a transistor has potential for digital displays and on-chipoptical interconnects. LET is a new light-emission concept, providingplanar light sources that can be easily integrated in substrates likesilicon, glass, paper using standard microelectronic techniques. Atransistor that emits light and is made from organic materials couldlead to cheaper digital displays and fast-switching light sources oncomputer chips. A transistor-based light source would switch much fasterthan a diode, and because of its planar design it could be more easilyintegrated onto computer chips, providing faster data transmissionacross chips than copper wire. The key to higher efficiency is athree-layer structure, with thin films stacked on top of one another.Current flows horizontally through the top and bottom layers onecarrying electrons and the other holes while carriers that wander intothe central layer recombine and emit photons. Because they're segregatedinto their own layer of material, the recombined carriers, known assinglets, don't run into other carriers, and their energy states changeto the point where they won't emit photons. Such quenching is one of themajor limitations of OLED efficiency.

In one embodiment, this invention is directed to a field effecttransistor (FET) device, comprising: (i) a gate electrode; (ii) a sourceelectrode and a drain electrode; (iii) dielectric layer on top of thegate electrode and an oligofuran or polyfuran of this invention betweensaid source and drain electrodes and in electrical contact therewith. Inanother embodiment, the FET further comprising a substrate with theoligofuran or polyfuran of this invention as a thin film thereon. Inanother embodiment, the transistor is a junction field effecttransistor. In another embodiment, the gate electrode is in electricalcontact with a p-type oligofuran/polyfuran organic semiconductor. Inanother embodiment, the oligofuran or polyfuran is n-typesemiconducting. In another embodiment, the oligofuran or polyfuran isp-type semiconducting.

In one embodiment, this invention is directed to a light effecttransistor (LET) device, comprising: (i) a gate electrode; (ii) a sourceelectrode and a drain electrode; (iii) dielectric layer on top of thegate electrode and an oligofuran of this invention between said sourceand drain electrodes and in electrical contact therewith. In anotherembodiment, the LET further comprising a substrate with the oligofuranof this invention as a thin film thereon. In another embodiment, thegate electrode is in electrical contact with a p-type oligofuran organicsemiconductor. In another embodiment, the oligofuran is n-typesemiconducting. In another embodiment, the oligofuran is p-typesemiconducting.

In one embodiment, this invention is directed to a complementary logiccircuit, an active matrix display, an active matrix LED displaycontaining organic transistor devices of this invention.

The organic semi-conductive layer may comprise one or more of a holetransporter, an electron transporter and a light emissive material. Oneor more further organic semi-conductive layers may be provided betweenthe anode and cathode. One or both of the anode and cathodeindependently may comprise the conductive polymer composition.

In one embodiment, if multiple layers of the device are formed bysolution processing then the skilled person will be aware of techniquesto prevent intermixing of adjacent layers, for example by crosslinkingof one layer before deposition of a subsequent layer or selection ofmaterials for adjacent layers such that the material from which thefirst of these layers is formed is not soluble in the solvent used todeposit the second layer. Alternatively, one layer is preferably formedby deposition from solution followed by heat treatment in order torender it substantially insoluble in the solvent used for deposition fora subsequent layer. In this way, cross-linking may be avoided.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following examples and preferred specificembodiments are, therefore, to be construed as merely illustrative, andnot limitative of the remainder of the disclosure in any way whatsoever.

EXAMPLES Preparation of Oligofurans

The oligofurans of this invention were prepared according to thesynthetic route as presented in FIG. 1.

General Information

¹H-NMR spectra were recorded on a 300 MHz spectrometer (Brücker) as asolution in ²H-Chloroform with tetramethylsilane (TMS) as the externalstandard. Chemical shifts are expressed in δ unit. 13C NMR spectra wererecorded on 62.50 MHz spectrometer (Brücker) as a solution in²H-Chloroform. UV-VIS absorption measurements were made on a Cary-50spectrometer (Varian). Steady state fluorescence measurements wereperformed on a Cary Eclipse fluorimeter (Varian) withexcitation/emission geometry at right angles. Fluorescence quantumyields were determined using a standard procedure (Lakowicz, J. R.,Principles of Fluorescence spectroscopy. 2nd ed.; KluwerAcademic/Plenum: New York, 1999; which is incorporated herein byreference). Quaterfuran in dioxane (λ_(abs)=364 nm, λ_(em)=393,418 nm,Φ=0.82) was used as a fluorescence reference (de Melo, J. S.; Elisei,F.; Gartner, C.; Aloisi, G. G.; Becker, R. S. J. Phys. Chem. A 2000,104, 6907; which is incorporated herein by reference). Quantum yieldmeasurements were made using four excitation wavelengths, the quantumyields were averaged over 20 measurements, and the errors were estimatedto be less than 5%. Propylene carbonate containing 0.1Mtetra-n-butylammonium tetrafluoroborate (TBABF₄) was used as a solvent.Ferrocene/ferrocenium redox couple (Fc/Fc⁺, 0.475 V vs SCE in CH₂Cl₂)was used as an internal reference for all measurements. Allelectrochemical measurements were performed under dry nitrogenatmosphere. Dry anhydrous propylene carbonate (PC) was purchased fromSigma-Aldrich and used as it is. tetra-n-butylammonium tetrafluoroborate(TBABF₄) Fluka) was dried under vacuum. Ferrocene powder (Fluka) wasused to establish an electrochemical reference. Ag/AgCl wire wasprepared by dipping silver wire in a solution of FeCl₃ and HCl.

Example 1 Preparation of Tributylstannyl-Bifuran and TrifuranIntermediates

2-(tributylstannyl)bifuran (1)

A solution of n-BuLi (7.7 mL, of 2.5M in hexanes, 19.2 mmol, 1.3equivalents) was added dropwise to a solution of bifuran (2 g, 14.9mmol) in dry THF (100 mL) at −78° C. under N₂. The mixture was allowedto come to room temperature and stirred for 1 h. To the white suspensionwas added dropwise Bu₃SnCl (4 mL, 14.9 mmol) at 0° C. and the reactionwas allowed to reach room temperature and stirred for 2 h. The mixturewas extracted with hexane, dried (MgSO₄) and evaporated. Seperation bychromatography using bacified silica (Et₃N) and hexane gave 1 (3.8 g,60% yield) as a colorless oil. ¹H NMR (300 MHz, CDCl₃): δ 0.85-0.91 (t,J=7.3 Hz, 9H), 1.03-1.13 (m, 6H), 1.26-1.39 (m, 6H), 1.48-1.63 (m, 6H),6.40-6.42 (m, 1H), 6.50 (d, J=3.3 Hz, 1H), 6.57 (dd, J=3.3, 6.0 Hz, 2H),7.34 (dd, J=0.7, 1.8 Hz, 1H) ppm. ¹³C NMR (300 MHz, CDCl₃): δ 10.2,13.7, 27.2, 28.9, 104.6, 105.0, 111.3, 123.0, 141.4, 147.5, 151.0, 160.9ppm

2-(tributylstannyl)terfuran (2) and 5,5″-Bis(tributylstannyl)2,2′:5′,2″-terfuran (5)

A 2.5M solution of n-BuLi in hexanes (3.2 mL, 8 mmol, 1.6 equivalents)was added dropwise to a solution of terfuran (1 g, 5 mmol) in dry THF(50 mL) at −78° C. under N₂. The mixture was allowed to come to roomtemperature and stirred for 30 min. To the white suspension was addeddropwise trimethyltin chloride (1.5 mL, 5.5 mmol) at 0° C. and thereaction was allowed to reach room temperature and stirred for 2 h. Themixture was extracted with hexane, dried (MgSO₄) and evaporated.Seperation using bacified silica (Net₃) and hexane gave 3 (1.05 g, 27%yield), 2 (890 mg, 48% yield) and starting material (110 mg, 11% yield).

2-(tributylstannyl)terfuran (2)

¹H NMR (300 MHz, CDCl₃): δ 0.83-0.90 (t, J=7.3 Hz, 9H), 1.03-1.08 (m,6H), 1.22-1.38 (dq, J=14.3, 7.2 Hz, 6H), 1.49-1.59 (m, 6H), 6.41-6.43(dd, J=3.4, 1.8 Hz, 1H), 6.52-6.60 (m, 5H), 7.37 (d, J=1.2 Hz, 1H) ppm.¹³C NMR (300 MHz, CDCl₃): δ 10.3, 13.7, 27.2, 28.9, 105.1, 105.4, 106.5,107.0, 111.4, 123.1, 141.8, 145.4, 146.5, 146.6, 150.6, 161.4 ppm. HRMS(FD): m/z calcd for C₂₄H₃₄O₃Sn: 490.1535. found 490.1534.

5,5″-Bis(tributylstannyl) 2,2′:5′,2″-terfuran (5)

¹H NMR (300 MHz, CDCl₃): δ 0.82-0.90 (t, J=7.2 Hz, 18H), 1.01-1.11 (m,12H), 1.23-1.37 (dq, J=7.2, 14.2 Hz, 12H), 1.48-1.60 (m, 12H), 6.53 (s,2H), 6.54-6.58 (q, J=3.2 Hz, 4H) ppm. ¹³C NMR (300 MHz, CDCl₃): δ 10.3,13.7, 27.2, 28.9, 105.1, 106.5, 123.1, 146.3, 150.8, 161.1 ppm. HRMS(FD): m/z calcd for C₃₆H₆₀O₃Sn₂: 778.2595. found 778.2599.

Example 2 Preparation of Oligofuran (4F)

α-quaterfuran (4F)

Pd(PPh₃)₄ (60 mg, 0.05 mmol, 5% mol) was added to 2,5′-(dibromo)bisfuran(289 mg, 1 mmol) and 2-tributyltinfuran (790 mg, 2.2 mmol) in drytoluene (20 mL), and the mixture was refluxed under N₂ for 5 h. Themixture was then cooled, evaporated and extracted with dichloromethane.The organic extract was dried (MgSO₄), evaporated, and the product wasseparated over a bacified silica (NEt₃) column, using hexane as eluent(R_(f)=0.2) to yield white, crystalline product. Characterization of 4Fwas described elsewhere (Kauffmann et al., Chemische Berichte 114, (11),3667-73 (1981)).

Example 3 Preparation of Oligofuran 5F

α-pentafuran (5F)

Pd(PPh₃)₄ (350 mg, 0.3 mmol, 10% mol) was added to2,5″-(dibromo)terfuran (600 mg, 1.39 mmol) and 2-tributyltinfuran (1.2g, 2.80 mmol) in dry toluene (150 mL), and the mixture was refluxedunder N₂ for 5 h. The mixture was then cooled, evaporated toapproximately 50 mL, and filtered. The filtrate was sublimed underreduced pressure (10⁻⁵ bar) at 165° C. to give 150 mg of 5F (32% yield),as bright yellow powder. ¹H NMR (300 MHz, CDCl₃): 6.43-6.45 (dd, J=3.4,1.8 Hz, 2H), 6.58-6.65 (m, 8H), 7.39-7.40 (m, 2H) ppm. ¹³C NMR (300 MHz,CDCl₃): δ 105.6, 107.1, 107.3, 107.4, 111.5, 142.1, 145.3, 145.5, 146.0,146.2 ppm. m.p. 208.7° C., HRMS (FD): m/z calcd for C₂₄H₁₄O₆: 332.0685.found 332.0681. Anal. calcd. for C₂₀H₁₂O₅: C, 72.29; H, 3.64. Found: C,72.42; H, 3.74.

Example 4 Preparation of Oligofuran 6F

α-sexifuran (6F)

Pd(PPh₃)₄ (600 mg, 0.5 mmol, 10% mol) was added to2,5′-(dibromo)bisfuran (681 mg, 2.35 mmol) and 2-(tributyltin)bisfuran(1) (2.1 g, 4.95 mmol) in dry toluene (200 mL), and the mixture wasrefluxed under N2 for 5 h. The mixture was then cooled, evaporated toapproximately 50 mL, and filtered. The filtrate was sublimed underreduced pressure (10⁻⁵ bar) at 190-200° C. to give 315 mg of 6F (34%yield), as bright yellow powder. ¹H NMR (300 MHz, CDCl₃): δ 6.43-6.45(m, 2H), 6.58-6.66 (m, 10H), 7.38-7.40 (d, 1.4 Hz, 2H) ppm. m.p. 260.5°C., HRMS (FD): m/z calcd for C₂₄H₁₄O₆: 398.0790. found 398.0787. Anal.calcd. for C₂₄H₁₄O₆: C, 72.36; H, 3.54. Found: C, 72.65; H, 3.58.

Example 5 Preparation of Oligofuran 7F

α-heptafuran (7F)

Pd(PPh₃)₄ (350 mg, 0.3 mmol, 10% mol) was added to 2,5′(dibromo)terfuran(500 mg, 1.4 mmol) and 2-(tributyltin)bifuran (1) (1.2 g, 2.8 mmol) indry toluene (250 mL), and the mixture was refluxed under N2 for 5 h. Themixture was then cooled, evaporated to approximately 50 mL, andfiltered. The filtrate was sublimed under reduced pressure (10⁻⁵ bar) at240° C. to give 315 mg of 6F (14% yield), as bright orange powder. m.p.298.8° C., HRMS (FD): m/z calcd for C₂₈H₁₆O₇: 464.0896. found: 464.0902.Anal. calcd. for C₂₈H₁₆O₇: C, 72.41; H, 3.47. Found: C, 72.12; H, 3.52

Example 6 Preparation of Oligofuran 8F

α-octafuran (8F)

Pd(PPh₃)₄ (305 mg, 0.3 mmol, 10% mol) was added to2,5′-(dibromo)bisfuran (355 mg, 1.2 mmol) and 2-(tributyltin)terfuran(2) (1.2 g, 2.4 mmol) in dry toluene (250 mL), and the mixture wasrefluxed under N2 for 5 h. The mixture was then cooled, evaporated toapproximately 50 mL, and filtered. The filtrate was sublimed underreduced pressure (10⁻⁵ bar) at 250° C. to give 315 mg of 6F (16% yield),as bright orange powder. m.p. 327.9° C., HRMS (FD): m/z calcd forC₃₂H₁₈O₈: 530.1002. found 530.1004.

Example 7 Preparation of Oligofuran 9F

5-bromo-2,2′:5′,2″-terfuran (6)

Into an ice bath cooled solution of terfuran (265 mg, 1.3 mmol) inbenzene (60 mL) was added N-bromosuccinimide (NBS, 211 mg, 1.2 mmol),and the mixture was stirred for 1 h in the dark. The mixture was thenextracted with a saturated solution of sodium hydrogencarbonate, and theorganic fraction was passed through a column of basified (NEt₃) silicausing hexane as eluent. 20 mL of dry toluene was added and hexane wasremoved by reduced pressure evaporation. The resulting solution was usedin the following step without further purification.

α-nonafuran(2,2′:5′,2″:5″,2′″:5′″,2″″:5″″,2′″″:5′″″,2″″″:5″″″,2″′″″:5″′″″,2″″″″-novifuran)(9F)

The above mentioned solution of 2-bromoterfuran (6) in toluene was addedto Pd(PPh₃)₄ (24 mg, 0.02 mmol, 10% mol) and 5,5″-Bis(tributylstannyl)2,2′:5′,2″-terfuran (5) (See Example 1) (80 mg, 0.1 mmol) in dry toluene(100 mL) and the mixture was refluxed under N₂ for 12 h. The mixture wasthen cooled, evaporated to approximately 50 mL, the precipitate wascollected by filtration, washed with hexane and sublimed under vacuum(10⁻² mbar) at 265° C. to give 9F as an orange powder. HRMS (FD): m/zcalcd for C₃₆H₂₀O₉: 596.1107. found 596.1109.

The product can be also separated by Soxlhet extraction, since it isslightly soluble in warm acetone. After 2 h. of Soxlhet with acetone thesoluble impurities were removed, a new fraction of acetone wasintroduced and the product can be seen in the flask as an orangeprecipitate.

Example 8 Photophysical Properties of the Oligofurans of this Invention

All electrochemical measurements were performed using PAR Potentiostatmodel 263A in a standard three-electrode, one compartment configurationequipped with Ag/AgCl wire, Pt wire and Pt disk electrode (dia. 1.6 mmfrom BASi), as the pseudo reference, counter electrode and workingelectrode, respectively. Pt disk electrodes were polished with aluminafollowed by sonication and further electropolished in 0.5M HClO4 bycycling between −0.23 and 1.25 V vs. a Ag/AgCl saturated NaCl electrode(BASi). The electrolytic medium contained anhydrous propylene carbonate(PC) and 0.1M tetrabutylamonium tetrafluoroborat (TBABF₄) aselectrolyte. All electrochemical solutions were purged with dry N₂ for15 minutes at least. Under these conditions, a Fc/Fc+ standard wascalibrated to be 0.34 V. Monomer concentration was about 10⁻² M.

Oligofurans are highly fluorescent, with quantum yield ranging from 58%in 9F to 74% in 5F (Table 1, FIG. 8). The Stokes shift values are around0.25 eV for 3F-9F, and are substantially smaller than for thecorresponding oligothiophenes 3T-6T (around 0.40 eV), indicating thatoligofurans are more rigid. The solid state fluorescence of 6F showedpeaks that are red shifted 0.35 eV relative to their value in solution(FIG. 8). In addition to the smaller Stokes shift and closer packingmentioned above, the rigidity of oligofurans can be seen from thecalculated twisting potentials (FIG. 16). The energy required to twist6F was significantly greater than for 6T. For example, twisting 6F to a36° twist angle required 12.5 kcal/mol, while similar twisting in 6Trequired only 2.3 kcal/mol. The smaller size of oxygen atom compared tosulfur atom which lead to less steric demand in oligofurans compared tooligothiophenes may also contribute to the significant difference in therigidity. The above findings indicate that, in spite of bettersolubility, oligofurans are more rigid than oligothiophene.

Table 1, provides the absorption, fluorescence quantum yield and redoxproperties of the oligofurans of this invention.

TABLE 1 Photophysical and electrochemical data for oligofurans. ε_(max)^(a) (M⁻¹ λ_(abs) ^(a) λ_(flu) ^(a) E_(ox) ^(c,d) HOMO^(e) cm⁻¹) (nm)(nm) Φ_(f) ^(a,b) (V) (eV) 5F 51000 388 421, 449 0.74 (0.36) 0.71 (0.67)−4.62 6F 53000 404 442, 472 0.69 (0.41) 0.67 (0.66) −4.55 7F 56000 417455, 485 0.67 0.66 (0.66) −4.51 8F 56000 423 467, 499 0.66 0.67 (0.68)−4.48 9F — 430 473, 507 0.58 — −4.45 ^(a)Measured in dioxane.^(b)Fluorescence quantum yields for the corresponding oligothiophen(nTs) (taken from Becker et al. J. Phys. Chem. 1996, 100, 18683) aregiven in parentheses. ^(c)Oxidation potentials measured in propylenecarbonate with 0.1M tetra-n-butylammonium tetrafluoroborate, referenceelectrode Ag/AgCl, Fc/Fc⁺ = 0.34 V vs. SCE under these conditions, scanrate: 100 mV/s. ^(d)Values in parentheses corresponds to Differentialpulse voltammogram (DPV) measurements (FIG. 15). ^(e)Calculated values(B3LYP/6-31G(d)). ^(f)Data were taken from de Melo, et al. J Phys.Chem.A 2000, 104, 6907, measured in MeCN.

Example 9 Crystallization and X-Ray Analysis of the Oligofurans of thisInvention

General X-Ray Procedures:

The X-ray diffraction data were collected on a Nonius KappaCCDdiffractometer, MoKα (λ=0.71073 Å), graphite monochromator, T=100(2)K.The data were processed with Denzo-Scalepack. The structures wererefined by full matrix least-squares based on F2 with SHELXL-97.

X-Ray Structural Analysis of α-Sexifuran (6F).

Compound 6F was crystallized from a heptane to give pale yellow crystals(plates). Crystal data: C₂₄H₁₄O₆, 0.10×0.10×0.01 mm³, Monoclinic,P2(1)/c, a=19.4403(16) Å, b=5.2922(4) Å, c=8.9457(0) Å, α=90 β=99.719(5)γ=90 from 18 degrees of data, Z=2, Fw=398.35, Dc=1.458 Mg·m⁻³, μ=0.106mm⁻¹. Data collection and processing: Bruker KappaApexll CCDdiffractometer, MoKα (λ=0.71073 Å), graphite monochromator, MiraColoptics, −23≦h≦23, −6≦k≦6, −6≦l≦10, frame scan width=0.5°, scan speed1.0° per 160 sec, typical peak mosaicity 0.67°, 6398 reflectionscollected, 1725 independent reflections (R-int=0.0984). The data wereprocessed with Apex2. Solution and refinement: Structure solved bydirect methods with Bruker Auto-Structure. Full matrix least-squaresrefinement based on F² with SHELXL-97 136 parameters with 0 restraints,final R₁=0.0501 (based on F²) for data with I>2σ(I) and R₁=0.1807 on3763 reflections, goodness-of-fit on F²=0.925, largest electron densitypeak=0.212 e/Å³ and hole −0.257 e/Å³.

X-Ray Structural Analysis of α-Terfuran (3F).

Compound 3F was crystallized from a heptane to give colorless crystals.Crystal data: C₁₂H₈O₃, 0.36×0.11×0.08 mm³, Monoclinic, Cc, a=17.982(5)Å, b=16.300(5) Å, c=10.747(2) Å, β=116.82 (3) from 27 degrees of data,V=2811.2 (15) Å³, Z=12, Fw=200.18, Dc=1.419 Mg·m⁻³, μ=0.103 mm⁻¹. Datacollection and processing: Nonius KappaCCD diffractometer, MoKα(λ=0.71073 Å), graphite monochromator, −24≦h≦18, −21≦k≦21, −13≦l≦14,frame scan width=1.0°, scan speed 1.0° per 80 sec, typical peakmosaicity 0.72°, 24341 reflections collected, 7021 independentreflections (R-int=0.0463). The data were processed withDenzo-Scalepack. Solution and refinement: Structure solved by Pattersonmethod with SHELXS-97. Full matrix least-squares refinement based on F²with SHELXL-97 406 parameters with 2 restraints, final R₁=0.0403 (basedon F²) for data with I>2σ(I) and R₁=0.0529 on 3543 reflections,goodness-of-fit on F²=1.016, largest electron density peak=0.369 e/Å³and hole −0.222 e/Å³.

X-Ray Structural Analysis of α-Tetrafuran (4F).

Compound 4F was crystallized from a heptane to give colorless crystals.Crystal data: C₁₆H₁₀O₄, 0.3×0.1×0.2 mm³, Monoclinic, P2₁/c (No. 14),a=11.2338(17) Å, b=5.3584(7) Å, c=10.9863(16) Å, β=114.828(5) from 20degrees of data, V=600.20(15) Å³, Z=2, Fw=266.24, Dc=1.473 Mg·m⁻³,μ=0.107 mm⁻¹. Data collection and processing: Bruker KappaApexII CCDdiffractometer, MoKα (λ=0.71073 Å), graphite monochromator, MiraColoptics, −12≦h≦12, −5≦k≦5, −12≦l≦12, frame scan width=0.5°, scan speed1.0° per 140 sec, typical peak mosaicity 0.46°, 5329 reflectionscollected, 869 independent reflections (R-int=0.0731). The data wereprocessed with Apex2. Solution and refinement: Structure solved bydirect methods with SHELXS. Full matrix least-squares refinement basedon F² with SHELXL-97 91 parameters with 0 restraints, final R₁=0.0428(based on F²) for data with I>2σ(I) and R₁=0.0837 on 863 reflections,goodness-of-fit on F²=1.026, largest electron density peak=0.191 e/Å³and hole −0.298 e/Å³.

Example 10 Synthesis of Compound IV-B (Dihexyl-6F)

General Information

¹H and ¹³C NMR spectra were recorded in solution on a 300 MHzspectrometer (Brücker) using ²H-chloroform as the solvent andtetramethylsilane (TMS) as the external standard. Chemical shifts areexpressed in δ unit. High resolution mass spectra were measured on aWaters Micromass GCT_Premier.

Synthesis

2-hexyl-5-iodofuran

A solution of n-BuLi (24.7 mL, 1.6 M in hexanes, 39.5 mmol, 1.4equivalents) was added dropwise to a solution of 2-hexylfuran (4.3 g,28.3 mmol) in dry tetrahydrofuran (THF, 50 mL) at −78° C. under N₂. Thereaction mixture was warmed to 0° C., stirred for 10 min and cooledagain to −78° C. To this solution was added slowly iodine (9.3 g, 36.7mmol) in 25 mL of THF, and the solution was warmed slowly to 0° C. andstirred for 2 h at 0° C. After addition of 100 mL of water, the solutionwas extracted with hexane. The organic layer was washed with aqueousNa₂S₂O₃ solution (30 mL) and water, dried over MgSO₄, filtered, andconcentrated. The crude product was purified by silica gel columnchromatography (elution with hexane) to afford 6 g of2-hexyl-5-iodofuran (76%) as a pale brownish oil. ¹H NMR (300 MHz,CDCl₃): δ6.37 (d, J=3.14 Hz, 1H), 5.88 (d, J=3.16 Hz, 1H), 2.60 (t,J=7.56, 7.56 Hz, 2H), 1.58 (td, J=15.11, 7.66, 7.66 Hz, 2H), 1.24-1.39(m, 6H), 0.86 (t, J=6.77, 6.77 Hz, 3H) ppm. ¹³C NMR (75 MHz, CDCl₃): δ162.3, 120.6, 108.0, 84.3, 31.6, 28.8, 28.3, 27.8, 22.6, 14.1 ppm. HRMS(FD): m/z calcd for C₁₀H₁₅IO: 278.0168. found 278.0172.

5-hexyl-2,2′-bifuran

Pd(PPh₃)₄ (1.15 g, 1 mmol, 5% mol) was added to 2-tributyltinfuran (7.05g, 20 mmol) and 2-hexyl-5-iodofuran (5.5 g, 20 mmol) in dry toluene (150mL) and the reaction mixture was refluxed under N₂ for 5 h. The mixturewas then cooled, separated with hexane, the organic layer was dried overMgSO₄, filtered, and concentrated. The crude product was purified bysilica gel column chromatography (elution with hexane) to afford 3.8 gof 5-hexyl-2,2′-bifuran (88%) as a colorless oil. ¹H NMR (300 MHz,CDCl₃): δ 7.35 (d, J=1.1 Hz, 1H), 6.39-6.45 (m, 3H), 6.00 (d, J=3.2 Hz,1H), 2.62 (t, J=7.6, 2H), 1.64 (td, J=2H), 1.28-1.34 (m, 6H) 0.87 (t,3H) ppm. ¹³C NMR (75 MHz, CDCl₃): δ 156.3, 147.0, 144.8, 141.3, 111.3,106.5, 105.9, 104.1, 31.6, 28.9, 28.1, 28.0, 22.6, 14.1 ppm. HRMS (FD):m/z calcd for C₁₄H₁₈O₂: 218.1307. found 218.1315.

Tributyl(5′-hexyl-[2,2′-bifuran]-5-yl)stannane)

A solution of n-BuLi (14.1 mL, 1.6 M in hexanes, 22.5 mmol, 1.3equivalents) was added dropwise to a solution of 2-hexyl-5-iodofuran(3.8 g, 17.4 mmol) in dry tetrahydrofuran (THF, 100 mL) at −78° C. underN₂. The reaction mixture was allowed to reach to room temperature andstirred for 1 h. The resulting mixture was cooled to −78° C., Bu₃SnCl(6.1 mL, 22.5 mmol) was added dropwise and the reaction mixture wasallowed to reach room temperature and stirred for 2 h. The mixture wasquenched with water, extracted with hexane, dried (MgSO₄), andevaporated. Flash chromatography on a basified (NEt₃) silica, usinghexane as eluent gave Tributyl(5′-hexyl-[2,2′-bifuran]-5-yl)stannane)(1.9 g, 20% yield) as a colorless oil. ¹H NMR (300 MHz, CDCl₃): ppm. ¹³CNMR (75 MHz, CDCl₃): δ 106.1, 155.9, 151.4, 145.7, 122.9, 106.4, 105.4,104.0, 31.6, 28.9, 28.8, 28.1, 28.0, 27.2 22.6, 14.7, 14.1, 10.2 ppm.FIRMS (FD): m/z calcd for C₂₆H₄₄O₂Sn: 508.2368. found 508.2374.

5,5′″″-dihexyl-2,2′:5′,2″:5″,2′″:5′″,2″″:5″″,2′″″-sexifuran (DH-6F)

Pd(PPh₃)₄ (115 mg, 0.1 mmol, 5% mol) was added to 2,5′-(dibromo)bisfuran(283 mg, 1 mmol) and Tributyl(5′-hexyl-[2,2′-bifuran]-5-yl)stannane (1g, 2 mmol) in dry toluene (200 mL) and the reaction mixture was refluxedunder N₂ for 5 h. The mixture was then cooled, concentrated toapproximately 50 mL, the residue was collected by filtration, washedwith acetone and sublimed under reduced pressure (10⁻² mbar) at 190-200°C. to give 190 mg of DH-6F (35% yield) as a bright yellow powder, m.p.261° C. ¹H NMR (400 MHz, 1,1,2,2-Tetrachloroethane-d₂): δ 6.62-6.67 (m,4H), 6.52 (d, J=3.54 Hz, 2H), 6.50 (d, J=3.19 Hz, 2H), 6.03 (d, J=3.32Hz, 2H), 2.64 (t, J=7.51, 7.51 Hz, 4H), 1.59-1.67 (m, 4H), 1.26-1.36 (m,12H), 0.86 (t, J=7.04 Hz, 6H). ¹³C NMR (100 MHz,1,1,2,2-Tetrachloroethane-d₂): δ 156.5, 144.9, 144.3, 143.7, 107.1,107.0, 106.7, 106.2, 106.1, 105.8, 105.7, 30.9, 28.2, 27.5, 27.3, 21.9,13.4 ppm. HRMS (FD): m/z calcd for C₃₆H₃₈O₆: 566.2668. found 566.2674

Example 11 Morphology of Selected Oligofuran Films of this Invention

Methods and Materials

Differential scanning calorimetry (DSC) measurements were performed on aTA Q200 DSC instrument. Elemental analysis was carried out with aFlashEA 1112 Thermo Finnigan CHN elemental analyzer. UV-vis absorptionmeasurements were made on a Cary-50 spectrometer (Varian). Steady statefluorescence measurements were performed on a Cary Eclipse fluorimeter(Varian) with the excitation/emission geometry at right angles.Fluorescence quantum yields were determined using a standard procedure(Lakowicz, J. R., Principles of Fluorescence spectroscopy. 2nd ed.;Kluwer Academic/Plenum: New York, 1999). Coumarine 30 in MeCN(λ_(abs)=403 nm, λ_(em), =480 nm, Φ_(f)=0.67) was used as a referencefor Φ_(f) measurements. (Jones, G.; Jackson, W. R.; Choi, C.; Bergmark,W. R. J. Phys. Chem. 1985, 89, 294-300).

Quantum yield measurements were made using four excitation wavelengths,the quantum yields were averaged over 20 measurements, and the errorswere estimated to be less than 5%. For solid state fluorescence, thecompound was measured as powder placed between two quartz slides.Propylene carbonate containing 0.1M tetra-n-butylammoniumtetrafluoroborate (TBABF₄) was used as a solvent. Ag/AgCl was used as areference electrode. A ferrocene/ferrocenium redox couple (Fc/Fc⁺=0.34 Vvs. saturated calomel electrode (SCE) in propylene carbonate (PC)) wasused as an internal reference for all measurements. All electrochemicalmeasurements were performed under a dry nitrogen atmosphere. Dryanhydrous PC was purchased from Sigma-Aldrich and used as it is. TBABF₄(Fluka) was dried under vacuum. Ferrocene powder (Fluka) was used toestablish an electrochemical reference. Ag/AgCl wire was prepared bydipping silver wire in a solution of FeCl₃ and HCl. THF and toluene weredistilled from sodium/benzophenone under an atmosphere of dry argonprior to use. Columns were prepared with silica gel (60-230 mesh).

Results

The film morphologies of oligofurans vacuum deposited on Si/SiO₂ werestudied by atomic force microscopy (AFM) and X-ray diffraction (XRD).AFM images of DH6F show a layer-by-layer deposition, with a layerthickness of ˜2.8-3.0 nm (FIG. 13 a). This is in agreement with the XRDmeasurements on these films, which reveal only a set of h00 diffractionpeaks for DH6F (FIG. 14 a) with corresponding d-spacing of 2.75 nm. Thisdistance corresponds to the calculated length of DH6F (3.89 nm) radii ofmethyl group of 0.2 nm) with a tilt angle of 45°. The film growth iscontinued in a layer-by-layer fashion, at least for the first threemonolayers (FIG. 13 b). For 8F, layer deposition is observed as well,with the thickness of 3 nm, indicating the molecules are aligned normalto the surface (the calculated length is 3.09 nm) (FIG. 13 c,d). Again,the layer-by-layer deposition is confirmed by XRD which shows a set ofh00 peaks (up to eights order), with d-spacing of 2.54 nm (FIG. 14 b).The morphology of 6F films is very different from that of 8F and DH-6Ffilms. AFM image indicates the formation of 1D ‘wires’ (FIG. 13 e),which form bundles at longer deposition times (FIG. 13 f). The XRDpattern of such film shows no selective alignment of thecrystallographic planes of 6F vs the substrate (FIG. 14 c). Similarresults were obtained when the molecules were deposited on OTS- orHMDS-modified Si/SiO₂ wafers (HMDS=hexamethyldisilazane).

Example 12 Electrochemistry of Oligofuran of this Invention

Materials and Methods

All electrochemical measurements were performed using PAR Potentiostatmodel 263A in a standard three-electrode, one compartment configurationequipped with Ag/AgCl wire, Pt wire, and Pt disk electrode (dia. 1.6 mmfrom BASi) as the pseudo reference, counter electrode, and workingelectrode, respectively. Pt disk electrodes were polished with aluminafollowed by sonication and further electropolished in 0.5M HClO₄ bycycling between −0.23 and 1.25 V vs. Ag/AgCl saturated NaCl electrode(BASi). The electrolytic medium contained anhydrous propylene carbonate(PC) and 0.1 M TBABF₄ as electrolyte. All electrochemical solutions werepurged with dry N₂ for at least 15 minutes. Under these conditions, aFc/Fc⁺ standard was calibrated to be 0.34 V. Monomer concentration wasabout 10⁻² M.

Results

Cyclic voltammetry (CV) of 5F-8F showed an irreversible oxidation peakat 0.71 V for 5F to 0.67 V vs. SCE for 8F (FIG. 2 a and Table 1 inExample 8, calibrated for Fc/Fc⁺=0.34 V vs. SCE). This is in agreementwith the calculated difference of only 0.14 eV in the HOMO energies of5F-8F (Table 1). Long oligofurans are significantly more electron richcompared to oligothiophenes, as evident from their relatively lowoxidation potentials. For comparison, the oxidation potentials of 3T and4T are 1.16 V and 1.14 V, respectively, under similar conditions. In thecases of 5F-7F, smooth polymer growth is observed during repetitivecycling (FIG. 2 b). The color of the formed film is yellowish orange inthe neutral state which changes to green upon doping.

Example 13 Synthesis of DPFB-6F Oligofuran

The synthetic scheme for the preparation of DPFB-6F oligofuran isdepicted in FIG. 17.

2′,2-(Tributylstannyl)-2,2′-bifuran (1)

A solution of n-BuLi (16 mL, 2.5M in hexanes, 40 mmol) was addeddropwise to a solution of bifuran (2.2 g, 16.5 mmol) in drytetrahydrofuran (THF, 50 mL) at −78° C. under N₂. The reaction mixturewas allowed to reach to room temperature and stirred for 1 h. Theresulting white suspension was cooled to −78° C., Bu₃SnCl (11 mL, 40mmol) was added dropwise and the reaction mixture was allowed to reachroom temperature and stirred for 2 h. The mixture was quenched withwater, extracted with hexane, dried (MgSO₄), and evaporated. Flashchromatography on a basified (NEt₃) silica, using hexane as eluent gave1 (1.6 g, 14% yield) as a colorless oil, and 2 1 (0.5 g, 7% yield) as acolorless oil.

5,5′-bis(perfluorophenyl)-2,2′-bifuran (DPFB-2F) andtributyl(5′-(perfluorophenyl)-[2,2′-bifuran]-5-yl)stannane (3)

Pd(PPh₃)₄ (10 mg, 0.3 mmol, 10% mol) was added tobromo-pentafluorobenzene (200 mg, 0.8 mmol) and 1 (0.5 g, 0.7 mmol) indry toluene (20 mL), and the reaction mixture was refluxed under N₂ for4 h. The mixture was then cooled, separated with water/hexane mixture,and the organic fractions were dried (MgSO₄) and evaporated. Flashchromatography on a basified (NEt₃) silica, using hexane as eluent gave3 (200 mg, 33% yield) and DPFB-2F (100 mg, 8% yield).

5,5′″″-bis(perfluorophenyl)-2,2′:5′,2″:5″,2′″:5′″,2″″:5″″,2′″″-sexifuran(DPFB-6F)

Pd(PPh₃)₄ (140 mg, 0.12 mmol, 10% mol) was added to2,2′-(dibromo)bifuran (170 mg, 0.6 mmol) and 3 (700 mg, 2.80 mmol) indry toluene (100 mL), and the reaction mixture was refluxed under N₂ for3 h. The mixture was then cooled, concentrated to approximately 20 mL,the residue was collected by filtration, washed with hexane and acetonsublimed under reduced pressure (10−2 mbar) at 260° C. to give 150 mg ofDPFB-6F (17% yield) as a bright yellow powder. HRMS (FD): m/z calcd forC₃₆H₁₂F₁₀O₆: 730.0474. found 730.0485. UV ABS and Fluorescence ofDPFB-6F is presented in FIG. 18.

What is claimed:
 1. An oligofuran represented by the structure of formula XIII:

wherein R₁, R₁′, R₁″, R₂, R₂″, R₃ and R₄ are independently hydrogen, C₄-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl, (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₂-C₁₈ alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈ alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl groups are optionally substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; R₂′ is C₄-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆ alkyl)-heterocycloalkyl, (C₀-C₁₈ alkyl)-aryl, (C₀-C₁₈ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, NO₂, halogen, CO₂—(C₁-C₁₈ alkyl), O—(C₂-C₁₈ alkyl), S—(C₁-C₁₈ alkyl), NH(C₁-C₁₈ alkyl), NHC(O)(C₁-C₁₈ alkyl) or N[(C₁-C₁₈ alkyl)][C(O)(C₁-C₁₈ alkyl)], halo-(C₁-C₁₈ alkyl), hydroxyl-(C₁-C₁₈ alkyl), amino-(C₁-C₁₈ alkyl), phenyl, aryl, cycloalkyl or heteroaryl; wherein said alkyl, aryl, cycloalkyl and heteroaryl groups are optionally substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), NHC(O)(C₁-C₆alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; or R₁ and R₂; R₁′ and R₂′; R₁″ and R₂″ combine to form a 4-8 membered ring comprising 0-3 double bonds and 0-3 heteroatoms selected from O, N, Se or S wherein said 4-8 membered ring is optionally substituted with 1-3 groups comprising C₁-C₁₈-alkyl, (C₀-C₆ alkyl)-cycloalkyl, (C₀-C₆ alkyl)-aryl, (C₀-C₆ alkyl)-heteroaryl, CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), dialkylamine, NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; wherein said aryl, cycloalkyl and heteroaryl groups of said (C₀-C₆ alkyl)-aryl, (C₀-C₆ alkyl)-cycloalkyl and (C₀-C₆ alkyl)-heteroaryl groups are optionally substituted with 1-3 groups comprising halide, C₁-C₆ alkyl, CN, CO₂H, OH, SH, NH₂, CO₂—(C₁-C₆ alkyl), O—(C₁-C₆ alkyl), S—(C₁-C₆ alkyl), NH(C₁-C₆ alkyl), N(R₄)(R₅), NHC(O)(C₁-C₆ alkyl) or N[(C₁-C₆ alkyl)][C(O)(C₁-C₆ alkyl)]; m is an integer between 1-50; m′ is an integer between 0-50 and n is an integer between 1-50.
 2. The oligofuran of claim 1, wherein said oligofuran is represented by the structure:


3. A fluorescent marker comprising the oligofuran of claim
 1. 4. A field effect transistor device comprising said oligofuran of claim
 1. 5. A light emitting transistor (LET) device comprising said oligofuran of claim
 1. 